ARM: dts: socfpga: add ltc2497 on arria10 devkit

Add the two ltc2497 devices that are on the SoCFPGA Arria10
Socdk board at addresses 0x14 and 0x16.
Signed-off-by: NAlan Tull <atull@kernel.org>
Signed-off-by: NDinh Nguyen <dinguyen@kernel.org>

arch/arm/boot/dts/socfpga_arria10_socdk.dtsi

@@ -48,6 +48,13 @@
 		};
 	};
 
+	ref_033v: 033-v-ref {
+		compatible = "regulator-fixed";
+		regulator-name = "0.33V";
+		regulator-min-microvolt = <330000>;
+		regulator-max-microvolt = <330000>;
+	};
+
 	soc {
 		clkmgr@ffd04000 {
 			clocks {
@@ -128,6 +135,18 @@
 	i2c-sda-falling-time-ns = <6000>;
 	i2c-scl-falling-time-ns = <6000>;
 
+	adc@14 {
+		compatible = "lltc,ltc2497";
+		reg = <0x14>;
+		vref-supply = <&ref_033v>;
+	};
+
+	adc@16 {
+		compatible = "lltc,ltc2497";
+		reg = <0x16>;
+		vref-supply = <&ref_033v>;
+	};
+
 	eeprom@51 {
 		compatible = "atmel,24c32";
 		reg = <0x51>;