usb: gadget: mv_u3d_core: let udc-core manage gadget->dev

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

drivers/usb/gadget/mv_u3d_core.c

@@ -1792,8 +1792,6 @@ static int mv_u3d_remove(struct platform_device *dev)
 
 	clk_put(u3d->clk);
 
-	device_unregister(&u3d->gadget.dev);
-
 	platform_set_drvdata(dev, NULL);
 
 	kfree(u3d);
@@ -1957,15 +1955,11 @@ static int mv_u3d_probe(struct platform_device *dev)
 	u3d->gadget.speed = USB_SPEED_UNKNOWN;	/* speed */
 
 	/* the "gadget" abstracts/virtualizes the controller */
-	dev_set_name(&u3d->gadget.dev, "gadget");
 	u3d->gadget.dev.parent = &dev->dev;
 	u3d->gadget.dev.dma_mask = dev->dev.dma_mask;
 	u3d->gadget.dev.release = mv_u3d_gadget_release;
 	u3d->gadget.name = driver_name;		/* gadget name */
-
-	retval = device_register(&u3d->gadget.dev);
-	if (retval)
-		goto err_register_gadget_device;
+	u3d->gadget.register_my_device = true;
 
 	mv_u3d_eps_init(u3d);
 
@@ -1991,8 +1985,6 @@ static int mv_u3d_probe(struct platform_device *dev)
 	return 0;
 
 err_unregister:
-	device_unregister(&u3d->gadget.dev);
-err_register_gadget_device:
 	free_irq(u3d->irq, &dev->dev);
 err_request_irq:
 err_get_irq: