ARM: dts: r8a7778: Use SoC-specific compat string for mmcif

Use the SoC-specific compat string for mmcif in DT for the r8a7778 SoC.
This is in keeping with the use of compat strings for mmcif for other
Renesas ARM based SoCs.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm/boot/dts/r8a7778.dtsi

@@ -369,7 +369,7 @@ scif5: serial@ffe45000 {
 	};
 
 	mmcif: mmc@ffe4e000 {
-		compatible = "renesas,sh-mmcif";
+		compatible = "renesas,mmcif-r8a7778", "renesas,sh-mmcif";
 		reg = <0xffe4e000 0x100>;
 		interrupts = <GIC_SPI 61 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&mstp3_clks R8A7778_CLK_MMC>;