Added RAK12035 Soil Moisture and Temperature Sensor (#2223)

variants/rak4631/platformio.ini

@@ -20,6 +20,7 @@ build_flags = ${nrf52_base.build_flags}
   -D LORA_TX_POWER=22
   -D SX126X_CURRENT_LIMIT=140
   -D SX126X_RX_BOOSTED_GAIN=1
+  -D ENV_INCLUDE_RAK12035=1
 build_src_filter = ${nrf52_base.build_src_filter}
   +<../variants/rak4631>
   +<helpers/sensors>