usb: gadget: at91_udc: let udc-core manage gadget->dev

By simply setting a flag, we can remove some
boilerplate code.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/at91_udc.c

@@ -1726,6 +1726,7 @@ static int at91udc_probe(struct platform_device *pdev)
 
 	/* init software state */
 	udc = &controller;
+	udc->gadget.register_my_device = true;
 	udc->gadget.dev.parent = dev;
 	if (pdev->dev.of_node)
 		at91udc_of_init(udc, pdev->dev.of_node);
@@ -1780,13 +1781,7 @@ static int at91udc_probe(struct platform_device *pdev)
 		DBG("clocks missing\n");
 		retval = -ENODEV;
 		/* NOTE: we "know" here that refcounts on these are NOPs */
-		goto fail0b;
-	}
-
-	retval = device_register(&udc->gadget.dev);
-	if (retval < 0) {
-		put_device(&udc->gadget.dev);
-		goto fail0b;
+		goto fail1;
 	}
 
 	/* don't do anything until we have both gadget driver and VBUS */
@@ -1857,8 +1852,6 @@ static int at91udc_probe(struct platform_device *pdev)
 fail2:
 	free_irq(udc->udp_irq, udc);
 fail1:
-	device_unregister(&udc->gadget.dev);
-fail0b:
 	iounmap(udc->udp_baseaddr);
 fail0a:
 	if (cpu_is_at91rm9200())
@@ -1892,8 +1885,6 @@ static int __exit at91udc_remove(struct platform_device *pdev)
 		gpio_free(udc->board.vbus_pin);
 	}
 	free_irq(udc->udp_irq, udc);
-	device_unregister(&udc->gadget.dev);
-
 	iounmap(udc->udp_baseaddr);
 
 	if (cpu_is_at91rm9200())