usb: replace ehci_*_remove() with usb_deregister()

The remove callbacks of EHCI drivers are often just a wrapper of
ehci_deregister.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
diff --git a/drivers/usb/host/ehci-mx6.c b/drivers/usb/host/ehci-mx6.c
index 602fec5..48889c1 100644
--- a/drivers/usb/host/ehci-mx6.c
+++ b/drivers/usb/host/ehci-mx6.c
@@ -451,17 +451,6 @@
 	return ehci_register(dev, hccr, hcor, &mx6_ehci_ops, 0, priv->init_type);
 }
 
-static int ehci_usb_remove(struct udevice *dev)
-{
-	int ret;
-
-	ret = ehci_deregister(dev);
-	if (ret)
-		return ret;
-
-	return 0;
-}
-
 static const struct udevice_id mx6_usb_ids[] = {
 	{ .compatible = "fsl,imx27-usb" },
 	{ }
@@ -472,7 +461,7 @@
 	.id	= UCLASS_USB,
 	.of_match = mx6_usb_ids,
 	.probe	= ehci_usb_probe,
-	.remove = ehci_usb_remove,
+	.remove = ehci_deregister,
 	.ops	= &ehci_usb_ops,
 	.platdata_auto_alloc_size = sizeof(struct usb_platdata),
 	.priv_auto_alloc_size = sizeof(struct ehci_mx6_priv_data),