* Add tx power calibration support
* Add a few tx power limits
* Hardcode default power to 12.5dB
* Disable TPC for now

v2: Address Jiri's comments
Signed-off-by: NNick Kossifidis <mickflemm@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>