usb: dwc3: gadget: Remove unused header inclusion

Remove sys_proto.h inclusion which is not used by the driver.

Signed-off-by: Vincent Tinelli <vincent.tinelli@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 25ccc01..1156662 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -23,7 +23,6 @@
 
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
-#include <asm/arch/sys_proto.h>
 
 #include "core.h"
 #include "gadget.h"