dt-bindings: serial: renesas,scif: Document r8a779h0 bindings

R-Car V4M (R8A779H0) SoC has the R-Car Gen4 compatible SCIF ports, so
document the SoC specific bindings.
Signed-off-by: Nghia Nguyen <nghia.nguyen.jg@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/49b854603c2c3ed6b2edd441f1d55160e0453b70.1709741175.git.geert+renesas@glider.beSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/serial/renesas,scif.yaml

@@ -68,6 +68,7 @@ properties:
               - renesas,scif-r8a779a0     # R-Car V3U
               - renesas,scif-r8a779f0     # R-Car S4-8
               - renesas,scif-r8a779g0     # R-Car V4H
+              - renesas,scif-r8a779h0     # R-Car V4M
           - const: renesas,rcar-gen4-scif # R-Car Gen4
           - const: renesas,scif           # generic SCIF compatible UART