arm64: tegra: Add PMU on Tegra210

The NVIDIA Tegra210 contains an ARM PMU v3 that can be used to gather
statistics about the processors and their memory system. Add a device
tree node so that this functionality can be exposed.
Reported-by: William Cohen <giantklein@gmail.com>
Tested-by: William Cohen <giantklein@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm64/boot/dts/nvidia/tegra210.dtsi

@@ -1439,6 +1439,16 @@ L2: l2-cache {
 		};
 	};
 
+	pmu {
+		compatible = "arm,armv8-pmuv3";
+		interrupts = <GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 145 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 146 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 147 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-affinity = <&{/cpus/cpu@0} &{/cpus/cpu@1}
+				      &{/cpus/cpu@2} &{/cpus/cpu@3}>;
+	};
+
 	timer {
 		compatible = "arm,armv8-timer";
 		interrupts = <GIC_PPI 13