Now that we can enable the usb_ether gadget, do it. This will be especially
useful for boards that don't have any ethernet controller, such as the ones
based on the A13 or A33.
Reviewed-by: Ćukasz Majewski <lukma@denx.de> Reviewed-by: Simon Glass <sjg@chromium.org> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>