ARM: dts: am3517-som: Associate cpu to regulator supply

The am3517-som is powered by vdd_core_reg, so let's add the
'cpu' device-tree node with the 'vdd_core' regulator as the core
supply.

Signed-off-by: Derald D. Woods <woods.technical@gmail.com>
Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am3517-som.dtsi

@@ -8,6 +8,14 @@
  * published by the Free Software Foundation.
  */
 
+/ {
+	cpus {
+		cpu@0 {
+			cpu0-supply = <&vdd_core_reg>;
+		};
+	};
+};
+
 &gpmc {
 	ranges = <0 0 0x30000000 0x1000000>;	/* CS0: 16MB for NAND */