arm64: dts: meson-g12a-x96-max: Add Gigabit Ethernet Support

Enable the network interface of the X96 Mac using an external
Realtek RTL8211F gigabit PHY, needing the same broken-eee properties
as the previous Amlogic SoC generations.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>