ath9k_hw: Cleanup Tx calibrations for AR9003 chips

Currently Tx IQ calibration is enabled by default for all AR9003
chips. But for AR9480, the calibration status should be read from
chip after processing ini. And also the carrier leak calibration
status is checked during init cal. As the init_cal is being called
for fast channel change too, the tx_cl status only be read after
full reset. Hence moving that into process ini function.

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>