dt-bindings: irqchip: renesas-irqc: Document r8a774b1 bindings

Document SoC specific bindings for RZ/G2N (r8a774b1) SoC.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/interrupt-controller/renesas,irqc.yaml

@@ -24,6 +24,7 @@ properties:
           - renesas,irqc-r8a7793        # R-Car M2-N
           - renesas,irqc-r8a7794        # R-Car E2
           - renesas,intc-ex-r8a774a1    # RZ/G2M
+          - renesas,intc-ex-r8a774b1    # RZ/G2N
           - renesas,intc-ex-r8a774c0    # RZ/G2E
           - renesas,intc-ex-r8a7795     # R-Car H3
           - renesas,intc-ex-r8a7796     # R-Car M3-W