arm64: dts: uniphier: change SD/eMMC node names to follow json-schema

Follow the standard nodename pattern "^mmc(@.*)?$" defined in
Documentation/devicetree/bindings/mmc/mmc-controller.yaml

Otherwise, after the dt-binding is converted to json-schema,
'make ARCH=arm64 dtbs_check' will show warnings like this:

  sdhc@5a000000: $nodename:0: 'sdhc@5a000000' does not match '^mmc(@.*)?$'
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

arch/arm64/boot/dts/socionext/uniphier-ld11.dtsi

@@ -433,7 +433,7 @@ peri_rst: reset {
 			};
 		};
 
-		emmc: sdhc@5a000000 {
+		emmc: mmc@5a000000 {
 			compatible = "socionext,uniphier-sd4hc", "cdns,sd4hc";
 			reg = <0x5a000000 0x400>;
 			interrupts = <0 78 4>;

arch/arm64/boot/dts/socionext/uniphier-ld20.dtsi

@@ -559,7 +559,7 @@ peri_rst: reset {
 			};
 		};
 
-		emmc: sdhc@5a000000 {
+		emmc: mmc@5a000000 {
 			compatible = "socionext,uniphier-sd4hc", "cdns,sd4hc";
 			reg = <0x5a000000 0x400>;
 			interrupts = <0 78 4>;
@@ -578,7 +578,7 @@ emmc: sdhc@5a000000 {
 			cdns,phy-dll-delay-sdclk-hsmmc = <21>;
 		};
 
-		sd: sdhc@5a400000 {
+		sd: mmc@5a400000 {
 			compatible = "socionext,uniphier-sd-v3.1.1";
 			status = "disabled";
 			reg = <0x5a400000 0x800>;

arch/arm64/boot/dts/socionext/uniphier-pxs3.dtsi

@@ -353,7 +353,7 @@ peri_rst: reset {
 			};
 		};
 
-		emmc: sdhc@5a000000 {
+		emmc: mmc@5a000000 {
 			compatible = "socionext,uniphier-sd4hc", "cdns,sd4hc";
 			reg = <0x5a000000 0x400>;
 			interrupts = <0 78 4>;
@@ -372,7 +372,7 @@ emmc: sdhc@5a000000 {
 			cdns,phy-dll-delay-sdclk-hsmmc = <21>;
 		};
 
-		sd: sdhc@5a400000 {
+		sd: mmc@5a400000 {
 			compatible = "socionext,uniphier-sd-v3.1.1";
 			status = "disabled";
 			reg = <0x5a400000 0x800>;