ekf2: add kconfig to disable wind estimation (off by default)

src/modules/ekf2/EKF/ekf.cpp

@@ -324,4 +324,8 @@ void Ekf::predictState(const imuSample &imu_delayed)
 	// Calculate filtered yaw rate to be used by the magnetometer fusion type selection logic
 	// Note fixed coefficients are used to save operations. The exact time constant is not important.
 	_yaw_rate_lpf_ef = 0.95f * _yaw_rate_lpf_ef + 0.05f * spin_del_ang_D / imu_delayed.delta_ang_dt;
+
+	// Calculate low pass filtered height rate
+	float alpha_height_rate_lpf = 0.1f * imu_delayed.delta_vel_dt; // 10 seconds time constant
+	_height_rate_lpf = _height_rate_lpf * (1.0f - alpha_height_rate_lpf) + _state.vel(2) * alpha_height_rate_lpf;
 }