ARM: zynq: dt: Add a fixed regulator for CPU voltage

To silence the warning
	cpufreq_cpu0: failed to get cpu0 regulator: -19
from the cpufreq driver regarding a missing regulator,
add a fixed regulator to the DT.
Zynq does not support voltage scaling and the CPU rail should always be
supplied with 1 V, hence it is added in the SOC-level dtsi.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>

arch/arm/boot/dts/zynq-7000.dtsi

@@ -25,6 +25,7 @@
 			reg = <0>;
 			clocks = <&clkc 3>;
 			clock-latency = <1000>;
+			cpu0-supply = <&regulator_vccpint>;
 			operating-points = <
 				/* kHz    uV */
 				666667  1000000
@@ -48,6 +49,15 @@
 		reg = < 0xf8891000 0x1000 0xf8893000 0x1000 >;
 	};
 
+	regulator_vccpint: fixedregulator@0 {
+		compatible = "regulator-fixed";
+		regulator-name = "VCCPINT";
+		regulator-min-microvolt = <1000000>;
+		regulator-max-microvolt = <1000000>;
+		regulator-boot-on;
+		regulator-always-on;
+	};
+
 	amba {
 		compatible = "simple-bus";
 		#address-cells = <1>;