ARM: dts: r8a7791: Add TPU device node

Enable support for the 4 PWM channels provided by the 16-bit Timer Pulse
Unit on R-Car M2-W, by adding a device node describing the TPU.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200316102540.28887-2-geert+renesas@glider.be

arch/arm/boot/dts/r8a7791.dtsi

@@ -291,6 +291,17 @@ pfc: pin-controller@e6060000 {
 			reg = <0 0xe6060000 0 0x250>;
 		};
 
+		tpu: pwm@e60f0000 {
+			compatible = "renesas,tpu-r8a7791", "renesas,tpu";
+			reg = <0 0xe60f0000 0 0x148>;
+			interrupts = <GIC_SPI 135 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&cpg CPG_MOD 304>;
+			power-domains = <&sysc R8A7791_PD_ALWAYS_ON>;
+			resets = <&cpg 304>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+
 		cpg: clock-controller@e6150000 {
 			compatible = "renesas,r8a7791-cpg-mssr";
 			reg = <0 0xe6150000 0 0x1000>;