realtek: dts: normalize Zyxel XGS1x10 DTS

realtek: dts: normalize Zyxel XGS1x10 DTS

The Zyxel XGS1x10 DTS overzealously tries to avoid redundancies. For
this the phy24/phy25 definitions were split into a common and a device
specific part. Understanding how these phys are defined is therefore
a little bit tricky. Add a little bit of redundancy to make the
definitions easier to read and understand in a single location.

Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Link: https://github.com/openwrt/openwrt/pull/22236
Signed-off-by: Robert Marko <robert.marko@sartura.hr>