FSK and LoRa Standard channels support

[adriansmares]

Summary

This PR fixes the FSK and LoRa Standard Channels support.

Changes

• Fix the IF chain 8 and 9 setup by adding an extra undocumented byte to the command.
  • I found this byte by retrieving the IF chain settings and seeing that they are not equivalent to the payload we are setting, and that it was missing one byte at the start, and had an extra 0 at the end. As such, I've tried to prepend a dummy byte, which worked.
• Support FSK transmissions (both TX and RX).
  • Fix the data rate reported by the RX packet. We used uint8_t instead of uint32_t, which made the returned bitrate be wrong.
  • The frequency deviation is automatically computed if not provided (v3 does not provide it).

Testing

I am currently running these changes on my own TTKGs, both EU868 and US915. Both the FSK and the standard channel work.