Some mavlink fixes to use vehicle_control_mode, WIP

src/modules/mavlink/orb_topics.h

@@ -95,6 +95,7 @@ struct mavlink_subscriptions {
 	int home_sub;
 	int airspeed_sub;
 	int navigation_capabilities_sub;
+	int control_mode_sub;
 };
 
 extern struct mavlink_subscriptions mavlink_subs;
@@ -111,6 +112,9 @@ extern struct navigation_capabilities_s nav_cap;
 /** Vehicle status */
 extern struct vehicle_status_s v_status;
 
+/** Vehicle control mode */
+extern struct vehicle_control_mode_s control_mode;
+
 /** RC channels */
 extern struct rc_channels_s rc;