arm64: dts: imx8dxl_evk: add adc0 support

Enable adc0 at imx8dxl_evk boards dts.
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8dxl-evk.dts

@@ -91,6 +91,13 @@ reg_usdhc2_vmmc: regulator-3 {
 		off-on-delay-us = <3480>;
 	};
 
+	reg_vref_1v8: regulator-adc-vref {
+		compatible = "regulator-fixed";
+		regulator-name = "vref_1v8";
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <1800000>;
+	};
+
 	mii_select: regulator-4 {
 		compatible = "regulator-fixed";
 		regulator-name = "mii-select";
@@ -102,6 +109,11 @@ mii_select: regulator-4 {
 	};
 };
 
+&adc0 {
+	vref-supply = <&reg_vref_1v8>;
+	status = "okay";
+};
+
 &eqos {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_eqos>;