ARM64: dts: marvell: armada-37xx: Wire PMUv3

The Cortex-A53s that power the Armada-37xx SoCs are equipped with
a PMUv3, just like most ARMv8 cores.

Advertise the PMUv3 presence in the device tree, and wire its
interrupt. This allows the perf subsystem to work correctly.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>

arch/arm64/boot/dts/marvell/armada-37xx.dtsi

@@ -81,6 +81,11 @@
 			     <GIC_PPI 10 IRQ_TYPE_LEVEL_HIGH>;
 	};
 
+	pmu {
+		compatible = "arm,armv8-pmuv3";
+		interrupts = <GIC_PPI 7 IRQ_TYPE_LEVEL_HIGH>;
+	};
+
 	soc {
 		compatible = "simple-bus";
 		#address-cells = <2>;