ARM64: dts: meson-gxl: Add support for Nexbox A95X

The Nexbox A95X exists with a Meson GXBB (S905) Soc or a Meson GXL SoC (S905X).
Add the S905X variant which uses the internal PHY instead of an external PHY.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>