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-generic.c b/drivers/usb/host/ehci-generic.c
index e0377ca..6291ed2 100644
--- a/drivers/usb/host/ehci-generic.c
+++ b/drivers/usb/host/ehci-generic.c
@@ -44,11 +44,6 @@
 	return ehci_register(dev, hccr, hcor, NULL, 0, USB_INIT_HOST);
 }
 
-static int ehci_usb_remove(struct udevice *dev)
-{
-	return ehci_deregister(dev);
-}
-
 static const struct udevice_id ehci_usb_ids[] = {
 	{ .compatible = "generic-ehci" },
 	{ }
@@ -59,7 +54,7 @@
 	.id	= UCLASS_USB,
 	.of_match = ehci_usb_ids,
 	.probe = ehci_usb_probe,
-	.remove = ehci_usb_remove,
+	.remove = ehci_deregister,
 	.ops	= &ehci_usb_ops,
 	.priv_auto_alloc_size = sizeof(struct generic_ehci),
 	.flags	= DM_FLAG_ALLOC_PRIV_DMA,