ath9k: fix AR_RX_FILTER for ar9462/ar9565 when rx stopped

When rx stopped, AR_RX_FILTER should be cleared, but in
ath9k_hw_setrxfilter(), ATH9K_RX_FILTER_CONTROL_WRAPPER will always
be set for ar9462/ar9565.

Fix this by moving the code in ath9k_hw_setrxfilter() to
ath_calcrxfilter().

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