arm: sun8i: sunxi-h3-h5: add dwmac-sun8i ethernet driver

The dwmac-sun8i is an ethernet MAC hardware that support 10/100/1000
speed.

This patch enable the dwmac-sun8i on Allwinner H3/H5 SoC Device-tree.
SoC H3/H5 have an internal PHY, so optionals syscon and ephy are set.

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>