CC1200 hotspot firmware v2.0 is out

We prepared a major rewrite, fixing most (all?) baseband transfer problems. The blue Service LED blinks happily now 🙂

This code is not compatible with older rpi-interface or Go M17 client. Make sure to update those!

Hotspot firmware: https://github.com/M17-Project/CC1200_HAT-fw
Updated rpi-interface: https://github.com/M17-Project/rpi-interface