ARM: dts: sunxi: Restore EMAC changes (boards)

The original dwmac-sun8i DT bindings have some issue on how to handle
integrated PHY and was reverted in last RC of 4.13.
But now we have a solution so we need to get back that was reverted.

This patch restore all boards DT about dwmac-sun8i
This reverts partially commit fe45174b

 ("arm: dts: sunxi: Revert EMAC changes")

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>