Add missing include to the USB driver core mode header file.

LUFA/Drivers/USB/Core/USBMode.h

@@ -64,6 +64,9 @@
 		#if !defined(__INCLUDE_FROM_USB_DRIVER)
 			#error Do not include this file directly. Include LUFA/Drivers/USB/USB.h instead.
 		#endif
+		
+	/* Includes: */
+		#include "../../../Common/Common.h"
 
 	/* Public Interface - May be used in end-application: */
 	#if defined(__DOXYGEN__)