ath9k: add calibration timeout for AR9002

ath9k: add calibration timeout for AR9002

ADC & I/Q calibrations could take infinite time to comple, since they
depend on received frames. In particular the I/Q mismatch calibration
requires receiving of OFDM frames for completion. But in the 2.4GHz
band, a station could receive only CCK frames for a very long time.

And while we wait for the completion of one of the mentioned
calibrations, the NF calibration is blocked. Moreover, in some
environments, I/Q calibration is unable to complete until a correct
noise calibration will be performed due to AGC behaviour.

In order to avoid delaying NF calibration on forever, limit the maximum
duration of ADCs & I/Q calibrations. If the calibration is not completed
within the maximum time, it will be interrupted and a next calibration
will be performed. The code that selects the next calibration has been
reworked to the loop so incompleted calibration will be respinned later.

Ð\90 maximum calibration time of 30 seconds was selected to give the
calibration enough time to complete and to not interfere with the long
(NF) calibration.

Run tested with AR9220.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200424004923.17129-7-ryazanov.s.a@gmail.com