USB: ehci-platform: remove update_device

The update_device callback is not needed and the function used here is
from the pci ehci driver. Without this patch we get a compile error if
ehci-platform is compiled without ehci-pci.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Cc: stable <stable@vger.kernel.org> [3.4]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-platform.c

@@ -75,8 +75,6 @@ static const struct hc_driver ehci_platform_hc_driver = {
 	.relinquish_port	= ehci_relinquish_port,
 	.port_handed_over	= ehci_port_handed_over,
 
-	.update_device		= ehci_update_device,
-
 	.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
 };