arm64: dts: renesas: spider-ethernet: Enable Ethernet Switch and SERDES

Enable Ethernet Switch and SERDES for R-Car S4-8 (r8a779f0).

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20221118120953.1186392-3-yoshihiro.shimoda.uh@renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>