ARM: dts: exynos: align HSOTG/USB node names

The DT schema expect HSOTG node names to be named "usb":

  exynos4210-smdkv310.dtb: hsotg@12480000: $nodename:0: 'hsotg@12480000' does not match '^usb(@.*)?'

Link: https://lore.kernel.org/r/20230120155404.323386-9-krzysztof.kozlowski@linaro.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

arch/arm/boot/dts/exynos3250.dtsi

@@ -365,7 +365,7 @@ sysmmu_fimd0: sysmmu@11e20000 {
 			#iommu-cells = <0>;
 		};
 
-		hsotg: hsotg@12480000 {
+		hsotg: usb@12480000 {
 			compatible = "samsung,s3c6400-hsotg";
 			reg = <0x12480000 0x20000>;
 			interrupts = <GIC_SPI 141 IRQ_TYPE_LEVEL_HIGH>;

arch/arm/boot/dts/exynos4.dtsi

@@ -362,7 +362,7 @@ exynos_usbphy: exynos-usbphy@125b0000 {
 			status = "disabled";
 		};
 
-		hsotg: hsotg@12480000 {
+		hsotg: usb@12480000 {
 			compatible = "samsung,s3c6400-hsotg";
 			reg = <0x12480000 0x20000>;
 			interrupts = <GIC_SPI 71 IRQ_TYPE_LEVEL_HIGH>;