usb: gadget: aspeed-vhub: constify usb_gadget_ops structure

The usb_gadget_ops structure can be const as it is only stored in
the ops field of a usb_gadget structure and this field is const.

Done with the help of Coccinelle.
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/udc/aspeed-vhub/dev.c

@@ -438,7 +438,7 @@ static int ast_vhub_udc_stop(struct usb_gadget *gadget)
 	return 0;
 }
 
-static struct usb_gadget_ops ast_vhub_udc_ops = {
+static const struct usb_gadget_ops ast_vhub_udc_ops = {
 	.get_frame	= ast_vhub_udc_get_frame,
 	.wakeup		= ast_vhub_udc_wakeup,
 	.pullup		= ast_vhub_udc_pullup,