dt-bindings: pwm: rcar: Add r8a774b1 support

Document RZ/G2N (R8A774B1) SoC bindings.
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/pwm/renesas,pwm-rcar.yaml

@@ -18,6 +18,7 @@ properties:
           - renesas,pwm-r8a7745   # RZ/G1E
           - renesas,pwm-r8a77470  # RZ/G1C
           - renesas,pwm-r8a774a1  # RZ/G2M
+          - renesas,pwm-r8a774b1  # RZ/G2N
           - renesas,pwm-r8a774c0  # RZ/G2E
           - renesas,pwm-r8a7778   # R-Car M1A
           - renesas,pwm-r8a7779   # R-Car H1