ekf2: selector use status timestamp for timeout rather than timestamp_sample (delayed time horizon)

- update stale checks for publication to use hrt elapsed time from
timestamp sample

src/modules/ekf2/EKF2Selector.hpp

@@ -120,7 +120,7 @@ private:
 		uORB::Subscription estimator_odometry_sub;
 		uORB::Subscription estimator_wind_sub;
 
-		uint64_t timestamp_sample_last{0};
+		uint64_t timestamp_last{0};
 
 		uint32_t accel_device_id{0};
 		uint32_t gyro_device_id{0};