ath9k: Update AR9462 initvals

HW peak detect calibration would fail for AR9300 chips and
we went for implementing the SW way of doing it instead of
HW doing the peak detect calibration.

Signed-off-by: Miaoqing Pan <miaoqing@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>