AP_ICEngine_TCA9554: add fuel pump power control

New aircraft have the fuel pump connected to the TCA9554 instead of the
ECU. This commit simply runs the fuel pump when the engine is running.

libraries/AP_ICEngine/AP_ICEngine.cpp

@@ -643,6 +643,10 @@ void AP_ICEngine::set_ignition(bool on)
     }
 #endif // AP_RELAY_ENABLED
 
+#if AP_ICENGINE_TCA9554_STARTER_ENABLED
+    tca9554_starter.set_ignition(on);
+#endif
+
 }
 
 /*

libraries/AP_ICEngine/AP_ICEngine_TCA9554.cpp

@@ -103,6 +103,9 @@ void AP_ICEngine_TCA9554::set_starter(bool on, AP_Int8 crank_direction)
     if (crank_direction) {
         value |= REVERSE;
     }
+    if (ignition_on) {
+        value |= FUEL_PUMP;
+    }
     TCA9554_set(value);
 }
 

libraries/AP_ICEngine/AP_ICEngine_TCA9554.h

@@ -9,6 +9,7 @@
 
 class AP_ICEngine_TCA9554 {
 public:
+    void set_ignition(bool on) { ignition_on = on; }
     void set_starter(bool on, AP_Int8 crank_direction);
 
 private:
@@ -17,6 +18,7 @@ class AP_ICEngine_TCA9554 {
     uint8_t last_state;
 
     bool initialised;
+    bool ignition_on;
 
     bool TCA9554_init();
     void TCA9554_set(uint8_t value);