ARM: dts: am57xx-beagle-x15: Add fixed regulator for aic3104's DVDD

The DVDD is supplied via TPS77018DBVT fixed regulator from vdd_3v3
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am57xx-beagle-x15.dts

@@ -35,6 +35,14 @@ vdd_3v3: fixedregulator-vdd_3v3 {
 		regulator-max-microvolt = <3300000>;
 	};
 
+	aic_dvdd: fixedregulator-aic_dvdd {
+		compatible = "regulator-fixed";
+		regulator-name = "aic_dvdd_fixed";
+		vin-supply = <&vdd_3v3>;
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <1800000>;
+	};
+
 	vtt_fixed: fixedregulator-vtt {
 		/* TPS51200 */
 		compatible = "regulator-fixed";