arm64: dts: renesas: r9a09g056: Add #mux-state-cells to usb20phyrst

The renesas,rzv2h-usb2phy-reset binding schema defines #mux-state-cells
as a required property. Add it to the usb20phyrst node to fix the
following warnings:

    arch/arm64/boot/dts/renesas/r9a09g056n48-rzv2n-evk.dtb: usb20phy-reset@15830000 (renesas,r9a09g056-usb2phy-reset): '#mux-state-cells' is a required property
    arch/arm64/boot/dts/renesas/r9a09g056n48-rzv2n-evk-cn15-emmc.dtb: usb20phy-reset@15830000 (renesas,r9a09g056-usb2phy-reset): '#mux-state-cells' is a required property
    arch/arm64/boot/dts/renesas/r9a09g056n48-rzv2n-evk-cn15-sd.dtb: usb20phy-reset@15830000 (renesas,r9a09g056-usb2phy-reset): '#mux-state-cells' is a required property

Fixes: 6a1b6f7 ("dt-bindings: reset: renesas,rzv2h-usb2phy: Add '#mux-state-cells' property")
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/31210e05f7189b466b30eedbdda3d11726dac279.1775575276.git.tommaso.merciai.xr@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Author: Tommaso Merciai

arch/arm64/boot/dts/renesas/r9a09g056.dtsi

@@ -1327,6 +1327,7 @@
 			resets = <&cpg 0xaf>;
 			power-domains = <&cpg>;
 			#reset-cells = <0>;
+			#mux-state-cells = <1>;
 			status = "disabled";
 		};