CONFIG_USB_HOST_ETHER is the framework that the drivers are dependent on
USB_HOST_ETHER. Use this as a menu and move the existing LAN75XX and
LAN78XX options under new menu. Finally update the defconfigs that need
CONFIG_USB_HOST_ETHER.
Signed-off-by: NChris Packham <judge.packham@gmail.com>
Reviewed-by: NSimon Glass <sjg@chromium.org>