ARM: dts: cygnus: Enable Performance Monitoring Unit

Add PMU capability to Cygnus so trace and performance profiling
can be used.
Signed-off-by: Jason Uy <jason.uy@broadcom.com>
Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

arch/arm/boot/dts/bcm-cygnus.dtsi

@@ -55,6 +55,11 @@ cpu@0 {
 
 	/include/ "bcm-cygnus-clock.dtsi"
 
+	pmu {
+		compatible = "arm,cortex-a9-pmu";
+		interrupts = <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>;
+	};
+
 	core {
 		compatible = "simple-bus";
 		ranges = <0x00000000 0x19000000 0x1000000>;