arm64: dts: intel: socfpga_agilex: move usbphy out of soc node

The usual usb-nop-xceiv USB phy node should be under root node, to fix
dtc warning:

    arch/arm64/boot/dts/intel/socfpga_agilex.dtsi:472.21-476.5:
        Warning (simple_bus_reg): /soc/usbphy@0: missing or empty reg/ranges property
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

arch/arm64/boot/dts/intel/socfpga_agilex.dtsi

@@ -124,6 +124,11 @@ timer {
 			     <1 10 0xf08>;
 	};
 
+	usbphy0: usbphy {
+		#phy-cells = <0>;
+		compatible = "usb-nop-xceiv";
+	};
+
 	soc {
 		#address-cells = <1>;
 		#size-cells = <1>;
@@ -469,11 +474,6 @@ uart1: serial1@ffc02100 {
 			status = "disabled";
 		};
 
-		usbphy0: usbphy@0 {
-			#phy-cells = <0>;
-			compatible = "usb-nop-xceiv";
-		};
-
 		usb0: usb@ffb00000 {
 			compatible = "snps,dwc2";
 			reg = <0xffb00000 0x40000>;