ARM: dts: sun8i: h3: Enable dwmac-sun8i on the Beelink X2

The dwmac-sun8i hardware is present on the Beelink X2.
It uses the internal PHY.

This patch create the needed emac node.

Signed-off-by: Marcus Cooper <codekipper@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
[wens@csie.org: Fixed typo in commit subject]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>