ekf2: move height rate lpf update where used

This also saves a bit of flash for board not using the WIND config

src/modules/ekf2/EKF/covariance.cpp

@@ -202,9 +202,9 @@ void Ekf::predictCovariance(const imuSample &imu_delayed)
 #if defined(CONFIG_EKF2_WIND)
 
 	// wind vel: add process noise
-	float wind_vel_nsd_scaled = _params.wind_vel_nsd * (1.f + _params.wind_vel_nsd_scaler * fabsf(
-					    _height_rate_lpf.getState()));
-	float wind_vel_process_noise = sq(wind_vel_nsd_scaled) * dt;
+	const float height_rate = _height_rate_lpf.update(_state.vel(2), imu_delayed.delta_vel_dt);
+	const float wind_vel_nsd_scaled = _params.wind_vel_nsd * (1.f + _params.wind_vel_nsd_scaler * fabsf(height_rate));
+	const float wind_vel_process_noise = sq(wind_vel_nsd_scaled) * dt;
 
 	for (unsigned index = 0; index < State::wind_vel.dof; index++) {
 		const unsigned i = State::wind_vel.idx + index;

src/modules/ekf2/EKF/ekf.cpp

@@ -274,8 +274,6 @@ void Ekf::predictState(const imuSample &imu_delayed)
 
 	// calculate a filtered horizontal acceleration this are used for manoeuvre detection elsewhere
 	_accel_horiz_lpf.update(corrected_delta_vel_ef.xy() / imu_delayed.delta_vel_dt, imu_delayed.delta_vel_dt);
-
-	_height_rate_lpf.update(_state.vel(2), imu_delayed.delta_vel_dt);
 }
 
 bool Ekf::resetGlobalPosToExternalObservation(const double latitude, const double longitude, const float altitude,

src/modules/ekf2/EKF/ekf.h

@@ -493,8 +493,10 @@ class Ekf final : public EstimatorInterface
 	static constexpr float _accel_horiz_lpf_time_constant = 1.f;
 	AlphaFilter<Vector2f> _accel_horiz_lpf{_accel_horiz_lpf_time_constant}; ///< Low pass filtered horizontal earth frame acceleration (m/sec**2)
 
+#if defined(CONFIG_EKF2_WIND)
 	static constexpr float _height_rate_lpf_time_constant = 10.f;
 	AlphaFilter<float> _height_rate_lpf{_height_rate_lpf_time_constant};
+#endif // CONFIG_EKF2_WIND
 
 	SquareMatrixState P{};	///< state covariance matrix