Draft: Remove duplicated setRfSwitchPins documentation

All radios that support RfSwitch define this method that simply forwards
to the `Module::setRfSwitchPins()` method. Previously, all these methods
duplicated the documentation as well, but this uses the doxygen \copydoc
to remove this duplication.

TODO: Apply to all radios if this approach is accepted

Author: matthijskooijman

src/modules/SX126x/SX126x.h

@@ -914,14 +914,7 @@ class SX126x: public PhysicalLayer {
    */
    int16_t setEncoding(uint8_t encoding) override;
 
-   /*!
-     \brief Some modules contain external RF switch controlled by two pins. This function gives RadioLib control over those two pins to automatically switch Rx and Tx state.
-     When using automatic RF switch control, DO NOT change the pin mode of rxEn or txEn from Arduino sketch!
-
-     \param rxEn RX enable pin.
-
-     \param txEn TX enable pin.
-   */
+   /*! \copydoc Module::setRfSwitchPins */
    void setRfSwitchPins(RADIOLIB_PIN_TYPE rxEn, RADIOLIB_PIN_TYPE txEn);
 
    /*!