Copter: added support for SERIAL_CONTROL message

ArduCopter/GCS_Mavlink.pde

@@ -1396,6 +1396,12 @@ void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
         }
         break;
 
+#if HAL_CPU_CLASS > HAL_CPU_CLASS_16
+    case MAVLINK_MSG_ID_SERIAL_CONTROL:
+        handle_serial_control(msg, gps);
+        break;
+#endif
+
 #if CAMERA == ENABLED
     case MAVLINK_MSG_ID_DIGICAM_CONFIGURE:      // MAV ID: 202
         camera.configure_msg(msg);