AP_GPS: example: do not instantiate AP_BoardLED unless the board supports it

libraries/AP_GPS/examples/GPS_AUTO_test/GPS_AUTO_test.cpp

@@ -33,8 +33,10 @@ const AP_HAL::HAL& hal = AP_HAL::get_HAL();                     //Declare "hal"
 
 static AP_BoardConfig board_config;
 
+#if AP_NOTIFY_GPIO_LED_3_ENABLED
 // create board led object
 AP_BoardLED board_led;
+#endif
 
 // create fake gcs object
 GCS_Dummy _gcs;                                                 //gcs stands for Ground Control Station
@@ -61,8 +63,10 @@ void setup()
 
     board_config.init();
 
+#if AP_NOTIFY_GPIO_LED_3_ENABLED
     // Initialise the leds
     board_led.init();
+#endif
 
     // Initialize the UART for GPS system
     serial_manager.init();