Add function to change register (REG_INVERTIQ) to support communication node and gateway
The register does not exist in datasheet but use on but used in Semtech code.
Reference : https://github.com/intel-iot-devkit/upm/blob/master/src/sx1276/sx1276.cxx
* Add LoRa Simple Gateway/Node Exemple
Example how to use InvertIQ function to create a simple Gateway/Node logic.
* Add support for Arduino MKR WAN 1300 board
* Add new LoRa.setSPI(...) API to use radio with a different SPI interface
* Disable LoRa.onReceive(...) and LoRa.receive() on Arduino MKR WAN 1300
* Add errors on sketches not compatible with the Arduino MKR WAN 1300
