ARM: dts: r8a7792: add SMP support

Add the device tree nodes for the Advanced Power Management Unit (APMU)
and the second Cortex-A15 CPU core.
Use the "enable-method" prop  to point out that the APMU should be used
for the SMP support.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7792.dtsi

@@ -21,6 +21,7 @@ / {
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;
+		enable-method = "renesas,apmu";
 
 		cpu0: cpu@0 {
 			device_type = "cpu";
@@ -32,6 +33,15 @@ cpu0: cpu@0 {
 			next-level-cache = <&L2_CA15>;
 		};
 
+		cpu1: cpu@1 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a15";
+			reg = <1>;
+			clock-frequency = <1000000000>;
+			power-domains = <&sysc R8A7792_PD_CA15_CPU1>;
+			next-level-cache = <&L2_CA15>;
+		};
+
 		L2_CA15: cache-controller@0 {
 			compatible = "cache";
 			reg = <0>;
@@ -49,6 +59,12 @@ soc {
 		#size-cells = <2>;
 		ranges;
 
+		apmu@e6152000 {
+			compatible = "renesas,r8a7792-apmu", "renesas,apmu";
+			reg = <0 0xe6152000 0 0x188>;
+			cpus = <&cpu0 &cpu1>;
+		};
+
 		gic: interrupt-controller@f1001000 {
 			compatible = "arm,gic-400";
 			#interrupt-cells = <3>;