linux:SystemTimeSupport: make compatible with time64 (64-bit time_t)

[plan44]

Some environments (e.g. musl >=1.2.0, as used in OpenWrt) have switched to time64 - using a 64bit type for time_t to prevent year 2037 problems due to 32bit epoch time overflow.

This PR fixes a formatstring error that appears when time_t is 64bit. It does so in a way that keeps compatibility with 32bit time_t while now also compiling and working correctly for 64bit.

Testing:

• verified correctly building and running in a musl 1.2 based experimental build of mine (time64)
• verified still correctly working in a standard Linux build (time32)

[CLAassistant]

All committers have signed the CLA.

[github-actions]

PR #19985: Size comparison from 46b15d6 to 92c7559

Increases (5 builds for cc13x2_26x2, cyw30739, esp32, linux, nrfconnect)

platform	target	config	section	46b15d6	92c7559	change	% change
cc13x2_26x2	lock-ftd	LP_CC2652R7	(read only)	668283	668291	8	0.0
			.text	591656	591664	8	0.0
cyw30739	light	cyw930739m2evb_01	(read/write)	580822	580830	8	0.0
			.app_xip_area	457816	457824	8	0.0
esp32	all-clusters-app	c3devkit	(read only)	1019318	1019320	2	0.0
			.flash.text	1019318	1019320	2	0.0
linux	thermostat-no-ble	arm64	(read only)	2597460	2597476	16	0.0
			.rodata	166148	166164	16	0.0
nrfconnect	all-clusters-app	nrf52840dk_nrf52840	text	810552	810556	4	0.0

Decreases (1 build for cc13x2_26x2)

platform	target	config	section	46b15d6	92c7559	change	% change
cc13x2_26x2	lock-ftd	LP_CC2652R7	(read/write)	174860	174852	-8	-0.0

Full report (30 builds for cc13x2_26x2, cyw30739, efr32, esp32, k32w, linux, mbed, nrfconnect, p6, telink)

platform	target	config	section	46b15d6	92c7559	change	% change
cc13x2_26x2	all-clusters-app	LP_CC2652R7	(read only)	665755	665755	0	0.0
			(read/write)	187244	187244	0	0.0
			.bss	75892	75892	0	0.0
			.data	3356	3356	0	0.0
			.rodata	88059	88059	0	0.0
			.text	577380	577380	0	0.0
	all-clusters-minimal-app	LP_CC2652R7	(read only)	654531	654531	0	0.0
			(read/write)	197764	197764	0	0.0
			.bss	75188	75188	0	0.0
			.data	3356	3356	0	0.0
			.rodata	91563	91563	0	0.0
			.text	562652	562652	0	0.0
	lock-ftd	LP_CC2652R7	(read only)	668283	668291	8	0.0
			(read/write)	174860	174852	-8	-0.0
			.bss	72924	72924	0	0.0
			.data	3280	3280	0	0.0
			.rodata	76147	76147	0	0.0
			.text	591656	591664	8	0.0
	lock-mtd	LP_CC2652R7	(read only)	617699	617699	0	0.0
			(read/write)	146040	146040	0	0.0
			.bss	68644	68644	0	0.0
			.data	3280	3280	0	0.0
			.rodata	76027	76027	0	0.0
			.text	541184	541184	0	0.0
	pump-app	LP_CC2652R7	(read only)	678111	678111	0	0.0
			(read/write)	165888	165888	0	0.0
			.bss	73012	73012	0	0.0
			.data	3280	3280	0	0.0
			.rodata	88711	88711	0	0.0
			.text	588916	588916	0	0.0
	pump-controller-app	LP_CC2652R7	(read only)	663991	663991	0	0.0
			(read/write)	180128	180128	0	0.0
			.bss	73132	73132	0	0.0
			.data	3276	3276	0	0.0
			.rodata	84551	84551	0	0.0
			.text	578960	578960	0	0.0
	shell	LP_CC2652R7	(read only)	658206	658206	0	0.0
			(read/write)	190296	190296	0	0.0
			.bss	78196	78196	0	0.0
			.data	3360	3360	0	0.0
			.rodata	84814	84814	0	0.0
			.text	573076	573076	0	0.0
cyw30739	light	cyw930739m2evb_01	(read/write)	580822	580830	8	0.0
			.app_xip_area	457816	457824	8	0.0
			.bss	65968	65968	0	0.0
			.data	716	716	0	0.0
			.rodata	0	0	0	0.0
			.text	112	112	0	0.0
	lock	cyw930739m2evb_01	(read/write)	582390	582390	0	0.0
			.app_xip_area	459192	459192	0	0.0
			.bss	66160	66160	0	0.0
			.data	720	720	0	0.0
			.rodata	0	0	0	0.0
			.text	112	112	0	0.0
	ota-requestor-no-progress-logging	cyw930739m2evb_01	(read/write)	584582	584582	0	0.0
			.app_xip_area	462424	462424	0	0.0
			.bss	65176	65176	0	0.0
			.data	660	660	0	0.0
			.rodata	0	0	0	0.0
			.text	112	112	0	0.0
efr32	lighting-app	BRD4161A	(read/write)	1082704	1082704	0	0.0
			.bss	134772	134772	0	0.0
			.data	2048	2048	0	0.0
			.text	945864	945864	0	0.0
		BRD4161A+rpc	(read/write)	1137020	1137020	0	0.0
			.bss	151460	151460	0	0.0
			.data	2260	2260	0	0.0
			.text	983276	983276	0	0.0
		BRD4161A+rs911x	(read/write)	945656	945656	0	0.0
			.bss	140488	140488	0	0.0
			.data	2048	2048	0	0.0
			.text	803100	803100	0	0.0
	lock-app	BRD4161A+wf200	(read/write)	1122544	1122544	0	0.0
			.bss	140936	140936	0	0.0
			.data	2060	2060	0	0.0
			.text	979528	979528	0	0.0
	window-app	BRD4161A	(read/write)	1067980	1067980	0	0.0
			.bss	134852	134852	0	0.0
			.data	2076	2076	0	0.0
			.text	931032	931032	0	0.0
esp32	all-clusters-app	c3devkit	(read only)	1019318	1019320	2	0.0
			(read/write)	1487018	1487018	0	0.0
			.dram0.bss	71840	71840	0	0.0
			.dram0.data	14624	14624	0	0.0
			.flash.rodata	215128	215128	0	0.0
			.flash.text	1019318	1019320	2	0.0
			.iram0.text	62902	62902	0	0.0
		m5stack	(read only)	1073427	1073427	0	0.0
			(read/write)	489152	489152	0	0.0
			.dram0.bss	77360	77360	0	0.0
			.dram0.data	34144	34144	0	0.0
			.flash.rodata	245652	245652	0	0.0
			.flash.text	1068043	1068043	0	0.0
			.iram0.text	123267	123267	0	0.0
k32w	light	k32w061+release	(read/write)	660424	660424	0	0.0
			.bss	71292	71292	0	0.0
			.data	1992	1992	0	0.0
			.text	581340	581340	0	0.0
	lock	k32w061+release	(read/write)	686832	686832	0	0.0
			.bss	71764	71764	0	0.0
			.data	2004	2004	0	0.0
			.text	607264	607264	0	0.0
linux	chip-tool-no-interactive-ipv6only	arm64	(read only)	9928900	9928900	0	0.0
			(read/write)	675697	675697	0	0.0
			.bss	42641	42641	0	0.0
			.data	1152	1152	0	0.0
			.data.rel.ro	614632	614632	0	0.0
			.dynamic	528	528	0	0.0
			.got	13456	13456	0	0.0
			.init	24	24	0	0.0
			.init_array	192	192	0	0.0
			.rodata	473380	473380	0	0.0
			.text	7915844	7915844	0	0.0
	thermostat-no-ble	arm64	(read only)	2597460	2597476	16	0.0
			(read/write)	181793	181793	0	0.0
			.bss	88721	88721	0	0.0
			.data	1704	1704	0	0.0
			.data.rel.ro	83256	83256	0	0.0
			.dynamic	528	528	0	0.0
			.got	5088	5088	0	0.0
			.init	24	24	0	0.0
			.init_array	400	400	0	0.0
			.rodata	166148	166164	16	0.0
			.text	2191536	2191536	0	0.0
mbed	lock-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2448040	2448040	0	0.0
			.bss	215732	215732	0	0.0
			.data	5872	5872	0	0.0
			.text	1410684	1410684	0	0.0
nrfconnect	all-clusters-app	nrf52840dk_nrf52840	(read/write)	1175867	1175867	0	0.0
			bss	144666	144666	0	0.0
			rodata	141724	141724	0	0.0
			text	810552	810556	4	0.0
	all-clusters-minimal-app	nrf52840dk_nrf52840	(read/write)	1156735	1156735	0	0.0
			bss	143902	143902	0	0.0
			rodata	133656	133656	0	0.0
			text	800260	800260	0	0.0
p6	all-clusters-app	default	(read/write)	2564496	2564496	0	0.0
			.bss	150912	150912	0	0.0
			.data	2776	2776	0	0.0
			.text	1522760	1522760	0	0.0
	all-clusters-minimal-app	default	(read/write)	2510360	2510360	0	0.0
			.bss	150192	150192	0	0.0
			.data	2776	2776	0	0.0
			.text	1468624	1468624	0	0.0
	light-app	default	(read/write)	2440504	2440504	0	0.0
			.bss	142248	142248	0	0.0
			.data	2592	2592	0	0.0
			.text	1398768	1398768	0	0.0
	lock-app	default	(read/write)	2466776	2466776	0	0.0
			.bss	142096	142096	0	0.0
			.data	2600	2600	0	0.0
			.text	1425040	1425040	0	0.0
telink	light-switch-app	tlsr9518adk80d	(read/write)	799080	799080	0	0.0
			bss	72360	72360	0	0.0
			noinit	40416	40416	0	0.0
			text	565512	565512	0	0.0
	lighting-app	tlsr9518adk80d	(read/write)	819044	819044	0	0.0
			bss	73180	73180	0	0.0
			noinit	40416	40416	0	0.0
			text	581950	581950	0	0.0

[bzbarsky-apple]

@plan44 Please fix the restyled failure?