drm/usb: bind driver to correct device

While looking at plymouth on udl I noticed that plymouth was trying
to use its fb plugin not its drm one, it was trying to drmOpen a driver called
usb not udl, noticed that we actually had out driver pointing at the wrong
device.

Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_usb.c

@@ -18,7 +18,7 @@ int drm_get_usb_dev(struct usb_interface *interface,
 
 	usbdev = interface_to_usbdev(interface);
 	dev->usbdev = usbdev;
-	dev->dev = &usbdev->dev;
+	dev->dev = &interface->dev;
 
 	mutex_lock(&drm_global_mutex);