realtek: dts: drop EXTERNAL_SFP_PHY macro

realtek: dts: drop EXTERNAL_SFP_PHY macro

The EXTERNAL_SFP_PHY macro is very strange. It has attributes
sfp and media but is not linked to any SFP definition. There
is nothing that the kernel can evaluate better than the classic
PHY_C22 macro.

Remark! For the current D-Link DGS-1210 consumers this macro
should be converted to a PHY_C22_SFP in the future. As of now
there is no hardware to identify the proper gpios and define
and verify the corresponding SFP ports. Add a TODO comment
where needed.

Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Link: https://github.com/openwrt/openwrt/pull/23036
Signed-off-by: Robert Marko <robimarko@gmail.com>