ath9k_hw: Fix TX IQ calibration for AR9003

only for AR9485 (or) later chipsets TxIQ calibration
runs as part of AGC calibration. without this patch
TX IQ cal completion i.e. ar9003_hw_tx_iq_cal_run won't be executed
for AR9003

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