usb: gadget: amd5536udc: use udc-core's reset notifier

Replace usb_gadget_driver's disconnect with udc-core's reset notifier at
bus reset handler.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/udc/amd5536udc.c b/drivers/usb/gadget/udc/amd5536udc.c
index 606b900..de7e5e2 100644
--- a/drivers/usb/gadget/udc/amd5536udc.c
+++ b/drivers/usb/gadget/udc/amd5536udc.c
@@ -2871,7 +2871,7 @@
 			dev->driver->resume(&dev->gadget);
 			dev->sys_suspended = 0;
 		}
-		dev->driver->disconnect(&dev->gadget);
+		usb_gadget_udc_reset(&dev->gadget, dev->driver);
 		spin_lock(&dev->lock);
 
 		/* disable ep0 to empty req queue */