ARM: at91: Add PMU support for sama5d3

ARM Performance Monitor Units are available on the sama5d3, add the support in
the dtsi.

Tested with perf and oprofile on the sama5d31ek.
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/boot/dts/sama5d3.dtsi

@@ -48,6 +48,11 @@
 		};
 	};
 
+	pmu {
+		compatible = "arm,cortex-a5-pmu";
+		interrupts = <46 IRQ_TYPE_LEVEL_HIGH 0>;
+	};
+
 	memory {
 		reg = <0x20000000 0x8000000>;
 	};