AP_GPS: fixed a build warning

Debug() should not be exposed in public headers

libraries/AP_GPS/AP_GPS.cpp

@@ -134,7 +134,6 @@ AP_GPS::detect_instance(uint8_t instance)
 		}
 		uint32_t baudrate = pgm_read_dword(&_baudrates[dstate->last_baud]);
 		port->begin(baudrate, 256, 16);		
-        Debug("Switching to GPS Baudrate %d", baudrate);
 		dstate->last_baud_change_ms = now;
         send_blob_start(instance, _initialisation_blob, sizeof(_initialisation_blob));
     }

libraries/AP_GPS/AP_GPS.h

@@ -35,13 +35,6 @@
 #define GPS_MAX_INSTANCES 1
 #endif
 
-#define GPS_DEBUGGING 0
-#if GPS_DEBUGGING
- # define Debug(fmt, args ...)  do {hal.console->printf("%s:%d: " fmt "\n", __FUNCTION__, __LINE__, ## args); hal.scheduler->delay(1); } while(0)
-#else
- # define Debug(fmt, args ...)
-#endif
-
 class DataFlash_Class;
 class AP_GPS_Backend;