wifi: ath12k: Identify DFS channel when sending scan channel list command

WMI_CHAN_INFO_DFS flag should be set when configuring a DFS channel
included in scan channel list. Without it, firmware will not send a
probe request frame which is needed in connection to an AP configured
with hidden SSID/network_id. So fix this to allow probe request frames
to be sent in cases where a beacon frame has been seen on the channel
first.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4

Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230316041144.7770-1-quic_bqiang@quicinc.com