Commander: update home position yaw in case of EKF yaw reset

This makes sure the drone lands in the correct orientation
during RTL even if the initial yaw at takeoff was wrong.

src/modules/commander/Commander.hpp

@@ -155,6 +155,8 @@ private:
 
 	bool set_home_position();
 	bool set_home_position_alt_only();
+	void updateHomePositionYaw(float yaw);
+	void checkEkfResetCounters();
 
 	void update_control_mode();
 
@@ -360,6 +362,7 @@ private:
 	hrt_abstime	_timestamp_engine_healthy{0}; ///< absolute time when engine was healty
 
 	uint32_t	_counter{0};
+	uint8_t		_quat_reset_counter{0};
 
 	bool		_status_changed{true};
 	bool		_arm_tune_played{false};
@@ -420,6 +423,7 @@ private:
 	uORB::SubscriptionData<offboard_control_mode_s>		_offboard_control_mode_sub{ORB_ID(offboard_control_mode)};
 	uORB::SubscriptionData<vehicle_global_position_s>	_global_position_sub{ORB_ID(vehicle_global_position)};
 	uORB::SubscriptionData<vehicle_local_position_s>	_local_position_sub{ORB_ID(vehicle_local_position)};
+	uORB::SubscriptionData<vehicle_attitude_s>		_attitude_sub{ORB_ID(vehicle_attitude)};
 
 	// Publications
 	uORB::Publication<actuator_armed_s>			_armed_pub{ORB_ID(actuator_armed)};