Update XIAO_NRF_KIT RXEN Pin definition (#6717)

The XIAO NRF kit comes with a hat which has a slightly different pinout than the one supplied with the XIAO S3. At the last update, the RXEN pin was not moved with the rest.

variants/seeed_xiao_nrf52840_kit/variant.h

@@ -114,8 +114,8 @@ static const uint8_t SCK = PIN_SPI_SCK;
 
 #define SX126X_TXEN RADIOLIB_NC
 
-#define SX126X_RXEN D4
-#define SX126X_DIO2_AS_RF_SWITCH // DIO2 is used to control the RF switch really necessary!!!
+#define SX126X_RXEN D5           // This is used to control the RX side of the RF switch
+#define SX126X_DIO2_AS_RF_SWITCH // DIO2 is used to control the TX side of the RF switch
 #define SX126X_DIO3_TCXO_VOLTAGE 1.8
 
 /*