usb: gadget: add platform module alias where it is missing

Without it udev won't be able to load the driver once it notices the
device unbound.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/gadget/r8a66597-udc.c b/drivers/usb/gadget/r8a66597-udc.c
index 51b655f..db7a6de 100644
--- a/drivers/usb/gadget/r8a66597-udc.c
+++ b/drivers/usb/gadget/r8a66597-udc.c
@@ -1686,6 +1686,7 @@
 		.name =	(char *) udc_name,
 	},
 };
+MODULE_ALIAS("platform:r8a66597_udc");
 
 static int __init r8a66597_udc_init(void)
 {