dt-bindings: soc: renesas: Document RZ/N2H (R9A09G087) SoC

Add RZ/N2H (R9A09G087), its variants, and the rzn2h-evk evaluation board
in documentation.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/20250609203656.333138-2-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Author: pbrkr

Documentation/devicetree/bindings/soc/renesas/renesas.yaml

@@ -580,6 +580,16 @@ properties:
               - renesas,r9a09g077m44 # RZ/T2H with Quad Cortex-A55 + Dual Cortex-R52 - no security
           - const: renesas,r9a09g077
 
+      - description: RZ/N2H (R9A09G087)
+        items:
+          - enum:
+              - renesas,rzn2h-evk # RZ/N2H Evaluation Board (RTK9RZN2H0S00000BJ)
+          - enum:
+              - renesas,r9a09g087m04 # RZ/N2H with Single Cortex-A55 + Dual Cortex-R52 - no security
+              - renesas,r9a09g087m24 # RZ/N2H with Dual Cortex-A55 + Dual Cortex-R52 - no security
+              - renesas,r9a09g087m44 # RZ/N2H with Quad Cortex-A55 + Dual Cortex-R52 - no security
+          - const: renesas,r9a09g087
+
 additionalProperties: true
 
 ...