sx127x: implement LoRa driver for sx127x

[deadprogram]

This PR brings in the commits from the @ofauchon branch implementing the sx127x for LoRa communication.

[deadprogram]

This is now working with my PyBadge + LoRa Featherwing:

# TinyGo Lora RX/TX test
# ----------------------
main: create and start SX127x driver
main: sx127x found
main: Receiving Lora for 10 seconds
main: End Lora RX
LORA TX size= 12  ->  Hello TinyGO
main: Receiving Lora for 10 seconds
main: End Lora RX
LORA TX size= 12  ->  Hello TinyGO
main: Receiving Lora for 10 seconds

[deadprogram]

Merging after review from @ofauchon thanks!