wifi: ath12k: add handler for scan event WMI_SCAN_EVENT_DEQUEUED

wifi: ath12k: add handler for scan event WMI_SCAN_EVENT_DEQUEUED

When wlan interface is up, and 11d scan is sent to the firmware, then
firmware needs to spend couple of seconds to complete the 11d scan. If
normal scan from user space arrives to ath12k at this moment, then the
normal scan request is also sent to the firmware, but the scan started
event will be reported to ath12k until the 11d scan complete. When timed
out for the scan started in ath12k, ath12k stops the normal scan and the
firmware reports WMI_SCAN_EVENT_DEQUEUED to ath12k for the normal scan.
ath12k has no handler for the event and then timed out for the scan
completed in ath12k_scan_stop(), and ath12k prints the following error
message.

[ 1491.604750] ath12k_pci 0000:02:00.0: failed to receive scan abort comple: timed out
[ 1491.604756] ath12k_pci 0000:02:00.0: failed to stop scan: -110
[ 1491.604758] ath12k_pci 0000:02:00.0: failed to start hw scan: -110

Add a handler for WMI_SCAN_EVENT_DEQUEUED and then complete the scan to
get rid of the above error message.

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

Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230717034457.22162-1-quic_wgong@quicinc.com