[mrf24j40] Fix incorrect init of RFCON8 register

This was probably a copy/paste error from another register, but the datasheet
clearly states that this register should be set to 0x10, the RFVCO bit, rather
than bit 1, which is not defined in the datasheet at all.
WIP turn on debug for our  branch, and add commentary
Broadcast _often_ to help speed up debugging
[mrf24j40] Use values from datasheet with explanations

Instead of raw binary fields