In order to be able to get rid of the non-DM MDIO bus registered in mvneta driver, start using the DM registered one in Turris MOX board code. This also allows us to drop the hack introduced in MOX' -u-boot.dtsi file. Signed-off-by: Marek Behún <marek.behun@nic.cz> Reviewed-by: Stefan Roese <sr@denx.de>