dt-bindings: soc: renesas: renesas.yaml: Add renesas,rzn1d400-eb compatible

Add "renesas,rzn1d400-eb" which target the RZ/N1 EB board when an
RZ/N1D-DB daughter board is plugged on it.

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230209133507.150571-2-clement.leger@bootlin.com


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