Enable the ethernet controller for the Alt board. Pin muxing entries are
currently left out as r8a7794 pin control support isn't available yet.
We thus rely on the boot loader to configure ethernet pins for now.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>