'signal_lost' flag added to manual_control_setpoint and rc_channels topics to indicate signal loss immediately

src/modules/uORB/topics/manual_control_setpoint.h

@@ -51,6 +51,8 @@
 struct manual_control_setpoint_s {
 	uint64_t timestamp;
 
+	bool signal_lost;		/**< control signal lost, should be checked together with topic timeout */
+
 	float roll;			 	/**< ailerons roll / roll rate input */
 	float pitch;				/**< elevator / pitch / pitch rate */
 	float yaw;				/**< rudder / yaw rate / yaw */

src/modules/uORB/topics/rc_channels.h

@@ -94,6 +94,7 @@ struct rc_channels_s {
 	char function_name[RC_CHANNELS_FUNCTION_MAX][20];
 	int8_t function[RC_CHANNELS_FUNCTION_MAX];
 	uint8_t rssi;                       /**< Overall receive signal strength */
+	bool signal_lost;		/**< control signal lost, should be checked together with topic timeout */
 }; /**< radio control channels. */
 
 /**