ARM: dts: r8a7791: Add PMU device node

Enable support for the ARM Performance Monitor Units in the Cortex-A15
CPU cores on R-Car M2-W by adding a device node for the PMU.

New Linux output:

    hw perfevents: enabled with armv7_cortex_a15 PMU driver, 7 counters available
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7791.dtsi

@@ -126,6 +126,13 @@ pcie_bus_clk: pcie_bus {
 		clock-frequency = <0>;
 	};
 
+	pmu {
+		compatible = "arm,cortex-a15-pmu";
+		interrupts-extended = <&gic GIC_SPI 72 IRQ_TYPE_LEVEL_HIGH>,
+				      <&gic GIC_SPI 73 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-affinity = <&cpu0>, <&cpu1>;
+	};
+
 	/* External SCIF clock */
 	scif_clk: scif {
 		compatible = "fixed-clock";