arm: zynq: Add support for pmu

Zynq is standard PMU with 2 interrupt per core.
There is also access via register which is not used right now.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

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

@@ -15,6 +15,13 @@
 / {
 	compatible = "xlnx,zynq-7000";
 
+	pmu {
+		compatible = "arm,cortex-a9-pmu";
+		interrupts = <0 5 4>, <0 6 4>;
+		interrupt-parent = <&intc>;
+		reg = < 0xf8891000 0x1000 0xf8893000 0x1000 >;
+	};
+
 	amba {
 		compatible = "simple-bus";
 		#address-cells = <1>;