qcacmn: Prevent link down for SAP on DFS channel

For SAP on DFS channel, the PCIe link down should be prevented
so that HalPhy can access DDR memory to report Radar found event.

Change-Id: I5eb1076196c509f0279781dbe3269d62132aeabc
CRs-Fixed: 2712800

target_if/mlme/vdev_mgr/src/target_if_vdev_mgr_tx_ops.c

@@ -479,6 +479,10 @@ static QDF_STATUS target_if_vdev_mgr_start_send(
 		else
 			target_if_vdev_mgr_rsp_timer_stop(psoc, vdev_rsp,
 							  START_RESPONSE_BIT);
+	} else {
+		target_if_vdev_start_link_handler(vdev,
+						  param->channel.cfreq1,
+						  param->channel.cfreq2);
 	}
 	return status;
 }
@@ -614,6 +618,8 @@ static QDF_STATUS target_if_vdev_mgr_stop_send(
 		target_if_vdev_mgr_rsp_timer_stop(psoc, vdev_rsp,
 						  STOP_RESPONSE_BIT);
 		target_if_wake_lock_timeout_release(psoc, STOP_WAKELOCK);
+	} else {
+		target_if_vdev_stop_link_handler(vdev);
 	}
 	return status;
 }