The 32 MHz TCXO that clocks the SX1276 is powered from PA12 and was never
driven, so the radio had no clock at all. The user button was copied from
the Nucleo L073RZ and left on PC13, which carries DIO3 of the radio on this
board; it is PB2.
Adds lorawan_tx and lorawan_beacon, with the radio defaults of a public
LoRaWAN network in the 915 MHz band, and fills in the board page.
Assisted-by: Claude Code 4.8
Signed-off-by: Jorge Guzman <jorge.gzm@gmail.com>
c191bcb76d