use actuator_controls[8] for collective tilt for tiltrotor VTOL, instead of [4]

[4] is reserved for Flaps, so also having the tilt on it was preventing us from
using flaps on tiltrotors, and other ripple effects.
By using [8] the tilt is separated from all other channels - it requires to increase the size of
actuator_controls by 1 to 9.

Signed-off-by: Silvan Fuhrer <silvan@auterion.com>

src/modules/control_allocator/ActuatorEffectiveness/ActuatorEffectivenessTiltrotorVTOL.cpp

@@ -109,7 +109,7 @@ void ActuatorEffectivenessTiltrotorVTOL::updateSetpoint(const matrix::Vector<flo
 		actuator_controls_s actuator_controls_1;
 
 		if (_actuator_controls_1_sub.copy(&actuator_controls_1)) {
-			float control_tilt = actuator_controls_1.control[4] * 2.f - 1.f;
+			float control_tilt = actuator_controls_1.control[actuator_controls_s::INDEX_COLLECTIVE_TILT] * 2.f - 1.f;
 
 			// set control_tilt to exactly -1 or 1 if close to these end points
 			control_tilt = control_tilt < -0.99f ? -1.f : control_tilt;

src/modules/vtol_att_control/tiltrotor.cpp

@@ -531,7 +531,7 @@ void Tiltrotor::fill_actuator_outputs()
 	}
 
 	// Fixed wing output
-	fw_out[4] = _tilt_control;
+	fw_out[actuator_controls_s::INDEX_COLLECTIVE_TILT] = _tilt_control;
 
 	if (_params->elevons_mc_lock && _vtol_schedule.flight_mode == vtol_mode::MC_MODE) {
 		fw_out[actuator_controls_s::INDEX_ROLL]  = 0;