ath9k_hw: Update AR9003 high_power tx gain table

The high_power tx gain table is changed to match the low_ob_db tx gain
table for both 5G and 2G.

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