remove the landing gear from the attitude setpoint

- An new message is created just for the landing gear
- The old logic is repalaced by publishing this new topic

msg/CMakeLists.txt

@@ -66,6 +66,7 @@ set(msg_files
 	input_rc.msg
 	iridiumsbd_status.msg
 	irlock_report.msg
+	landing_gear.msg
 	landing_target_innovations.msg
 	landing_target_pose.msg
 	led_control.msg