Q estimator: Use all available sensor instances

src/modules/attitude_estimator_q/attitude_estimator_q_main.cpp

@@ -289,7 +289,7 @@ void AttitudeEstimatorQ::task_main()
 		if (!orb_copy(ORB_ID(sensor_combined), _sensors_sub, &sensors)) {
 			// Feed validator with recent sensor data
 
-			for (unsigned i = 0; i < 2; i++) {
+			for (unsigned i = 0; i < (sizeof(sensors.gyro_timestamp) / sizeof(sensors.gyro_timestamp[0])); i++) {
 				_voter_gyro.put(i, sensors.gyro_timestamp[i], &sensors.gyro_rad_s[i * 3], sensors.gyro_errcount[i]);
 				_voter_accel.put(i, sensors.accelerometer_timestamp[i], &sensors.accelerometer_m_s2[i * 3], sensors.accelerometer_errcount[i]);
 				_voter_mag.put(i, sensors.magnetometer_timestamp[i], &sensors.magnetometer_ga[i * 3], sensors.magnetometer_errcount[i]);