arm64: dts: mediatek: mt8516: add auxadc node

Add node for the auxadc IP. The IP is compatible with the one found
in MT8173 SoC.
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Link: https://lore.kernel.org/r/20201012205218.3010868-2-fparent@baylibre.comSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>

arch/arm64/boot/dts/mediatek/mt8516.dtsi

@@ -470,5 +470,15 @@ usb0_port: usb-phy@11110800 {
 				#phy-cells = <1>;
 			};
 		};
+
+		auxadc: adc@11003000 {
+			compatible = "mediatek,mt8516-auxadc",
+				     "mediatek,mt8173-auxadc";
+			reg = <0 0x11003000 0 0x1000>;
+			clocks = <&topckgen CLK_TOP_AUX_ADC>;
+			clock-names = "main";
+			#io-channel-cells = <1>;
+			status = "disabled";
+		};
 	};
 };