Cherry pick the directory and voted_sensors_update.h from PR #9756.

Consolidate _update_params() methods for improved inheritance from the LandDetector base class.
Move common uORB::Subscriptions to the base class for inheritance.
Deprecate redundant override methods.

src/modules/land_detector/FixedwingLandDetector.h

@@ -42,10 +42,9 @@
 
 #pragma once
 
+#include <matrix/math.hpp>
 #include <uORB/Subscription.hpp>
 #include <uORB/topics/airspeed.h>
-#include <uORB/topics/vehicle_acceleration.h>
-#include <uORB/topics/vehicle_local_position.h>
 
 #include "LandDetector.h"
 
@@ -60,12 +59,13 @@ public:
 	FixedwingLandDetector();
 
 protected:
-	void _update_params() override;
-	void _update_topics() override;
 
 	bool _get_landed_state() override;
+
 	float _get_max_altitude() override;
 
+	void _update_topics() override;
+
 private:
 
 	/** Time in us that landing conditions have to hold before triggering a land. */
@@ -73,13 +73,8 @@ private:
 	static constexpr hrt_abstime FLYING_TRIGGER_TIME_US = 0_us;
 
 	uORB::Subscription _airspeed_sub{ORB_ID(airspeed)};
-	uORB::Subscription _parameter_update_sub{ORB_ID(parameter_update)};
-	uORB::Subscription _vehicle_acceleration_sub{ORB_ID(vehicle_acceleration)};
-	uORB::Subscription _vehicle_local_position_sub{ORB_ID(vehicle_local_position)};
 
 	airspeed_s _airspeed{};
-	vehicle_acceleration_s _vehicle_acceleration{};
-	vehicle_local_position_s _vehicle_local_position{};
 
 	float _airspeed_filtered{0.0f};
 	float _velocity_xy_filtered{0.0f};
@@ -93,7 +88,6 @@ private:
 		(ParamFloat<px4::params::LNDFW_VEL_XY_MAX>) _param_lndfw_vel_xy_max,
 		(ParamFloat<px4::params::LNDFW_VEL_Z_MAX>)  _param_lndfw_vel_z_max
 	);
-
 };
 
 } // namespace land_detector