ARM: dts: r8a7790: Add APMU nodes

Add DT nodes for the Advanced Power Management Units (APMU), and use the
enable-method to point out that the APMU should be used for SMP
support.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7790.dtsi

@@ -44,6 +44,7 @@
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;
+		enable-method = "renesas,apmu";
 
 		cpu0: cpu@0 {
 			device_type = "cpu";
@@ -164,6 +165,18 @@
 		};
 	};
 
+	apmu@e6151000 {
+		compatible = "renesas,r8a7790-apmu", "renesas,apmu";
+		reg = <0 0xe6151000 0 0x188>;
+		cpus = <&cpu4 &cpu5 &cpu6 &cpu7>;
+	};
+
+	apmu@e6152000 {
+		compatible = "renesas,r8a7790-apmu", "renesas,apmu";
+		reg = <0 0xe6152000 0 0x188>;
+		cpus = <&cpu0 &cpu1 &cpu2 &cpu3>;
+	};
+
 	gic: interrupt-controller@f1001000 {
 		compatible = "arm,gic-400";
 		#interrupt-cells = <3>;