RC_Channel: tradheli support for turbine start

libraries/RC_Channel/RC_Channel.cpp

@@ -501,6 +501,7 @@ void RC_Channel::init_aux_function(const aux_func_t ch_option, const AuxSwitchPo
     case AUX_FUNC::SCRIPTING_8:
     case AUX_FUNC::VTX_POWER:
     case AUX_FUNC::OPTFLOW_CAL:
+	case AUX_FUNC::TURB_START:
         break;
     case AUX_FUNC::AVOID_ADSB:
     case AUX_FUNC::AVOID_PROXIMITY:

libraries/RC_Channel/RC_Channel.h

@@ -203,6 +203,7 @@ public:
         WIND_VANE_DIR_OFSSET= 97, // flag for windvane direction offset input, used with windvane type 2
         TRAINING            = 98, // mode training
         AUTO_RTL =            99, // AUTO RTL via DO_LAND_START
+		TURB_START =         98, // initialize turbine start sequence
 
         // entries from 100-150  are expected to be developer
         // options used for testing