ath9k_hw: add a helper for Power Amplifier calibration for AR9002

The code can be simplified and shared between two locations if we bring
this into a helper. During reset we do not account for the skip count.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
1 file changed