dt-bindings: mmc: renesas,sdhi: Document R-Car V4M support

Document support for the SD Card/MMC Interface in the Renesas R-Car V4M
(R8A779H0) SoC.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/fffc5a0a73c4cc8e8d7c5d93679531cc24e006ca.1707915511.git.geert+renesas@glider.beSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml

@@ -67,6 +67,7 @@ properties:
               - renesas,sdhi-r8a779a0  # R-Car V3U
               - renesas,sdhi-r8a779f0  # R-Car S4-8
               - renesas,sdhi-r8a779g0  # R-Car V4H
+              - renesas,sdhi-r8a779h0  # R-Car V4M
           - const: renesas,rcar-gen4-sdhi # R-Car Gen4
 
   reg: