stm32: Merge chip flash memory bank regions

[tact1m4n3]

Merge chip flash memory bank regions

The script used for generating all the chip definitions for the stm32 port doesn't merge some regions of flash memory belonging to the same bank. Take this example from a chip definition file in embassy-rs/stm32-data-generated. These regions have to be merged into a single MemoryRegion. This patch fixes this issue.

"memory": [
    {
      "name": "BANK_1_REGION_1",         <<<<<<<<<HERE
      "kind": "flash",
      "address": 134217728,
      "size": 65536,
      "settings": {
        "erase_size": 16384,
        "write_size": 4,
        "erase_value": 255
      }
    },
    {
      "name": "BANK_1_REGION_2",        <<<<<<<<<HERE
      "kind": "flash",
      "address": 134283264,
      "size": 65536,
      "settings": {
        "erase_size": 65536,
        "write_size": 4,
        "erase_value": 255
      }
    },
    {
      "name": "BANK_1_REGION_3",        <<<<<<<<<HERE
      "kind": "flash",
      "address": 134348800,
      "size": 393216,
      "settings": {
        "erase_size": 131072,
        "write_size": 4,
        "erase_value": 255
      }
    },
    {
      "name": "CCMRAM",
      "kind": "ram",
      "address": 268435456,
      "size": 65536
    },
    {
      "name": "SRAM",
      "kind": "ram",
      "address": 536870912,
      "size": 114688
    },
    {
      "name": "SRAM2",
      "kind": "ram",
      "address": 536985600,
      "size": 16384
    }
  ],

[mattnite]

I'm not sure if the information on where the different regions are located is useful, but I'll allow this patch for now. We can break out that information to users some other way in the future.

[tact1m4n3]

I would rather have this merged after #259 because they conflict and merging this afterwards would make it clearer what changes belonged to this patch.

[mattnite]

@tact1m4n3 please fix the merge conflicts