dt-bindings: mmc: renesas,sdhi: Fix RZ/V2M clock description

dt-bindings: mmc: renesas,sdhi: Fix RZ/V2M clock description

The SD Card/MMC interface on the Renesas RZ/V2M SoC uses 4 clocks, like
on RZ/G2L SoCs.

The current description specifies 3 clocks, like on R-Car Gen3, which
will lead to "make dtbs_check" failures:

    arch/arm64/boot/dts/renesas/r9a09g011-v2mevk2.dtb: mmc@85000000: clocks: [[3, 1, 18], [3, 1, 20], [3, 1, 19], [3, 1, 17]] is too long
	    From schema: Documentation/devicetree/bindings/mmc/renesas,sdhi.yaml

Fixes: c8dbdf2a1044951b ("dt-bindings: mmc: renesas,sdhi: Document RZ/V2M support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/054c9f4dbb0bb1525f780d1e85c724436465c20c.1673270716.git.geert+renesas@glider.be
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>