qcacmn: Add timestamp param and enable foreign channel exit in scan event

Add timestamp parameter in scan event received from FW to aid
in calculating dwell time and overall channel switch time in
off-channel operations.

Enable foreign channel exit event inorder to be notified
by FW through the scan event.

Change-Id: I4ba028756ee7db35f6528c0554b09c73087184a7
CRs-Fixed: 2056330

wmi_unified_tlv.c

@@ -16399,6 +16399,7 @@ static QDF_STATUS extract_vdev_scan_ev_param_tlv(wmi_unified_t wmi_handle,
 	param->requester = evt->requestor;
 	param->scan_id = evt->scan_id;
 	param->vdev_id = evt->vdev_id;
+	param->timestamp = evt->tsf_timestamp;
 
 	return QDF_STATUS_SUCCESS;
 }