ARM: dts: am571x-idk: Add cpu0 vdd supply

Add vdd-supply as smps12_reg for cpu0.
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am571x-idk.dts

@@ -117,3 +117,7 @@ &mmc2 {
 	pinctrl-1 = <&mmc2_pins_hs>;
 	pinctrl-2 = <&mmc2_pins_ddr_rev20 &mmc2_iodelay_ddr_conf>;
 };
+
+&cpu0 {
+	vdd-supply = <&smps12_reg>;
+};