ath11k: Enable remain-on-channel support on WCN6750

Enable remain on channel support on WCN6750 as it is needed for
GAS, Passpoint.

Tested-on: WCN6750 hw1.0 AHB WLAN.MSL.1.0.1-00887-QCAMSLSWPLZ-1

Signed-off-by: Manikanta Pubbisetty <quic_mpubbise@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220901080656.3450-1-quic_mpubbise@quicinc.com