ARM: dts: Add pmu sysreg node to exynos5250 and exynos5420

This patch adds pmusysreg node to exynos5250 and exynos5420 dtsi files to
handle PMU register accesses in a centralized way using syscon driver

Signed-off-by: Leela Krishna Amudala <l.krishna@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

Documentation/devicetree/bindings/arm/samsung/pmu.txt

@@ -0,0 +1,15 @@
+SAMSUNG Exynos SoC series PMU Registers
+
+Properties:
+ - compatible : should contain two values. First value must be one from following list:
+		   - "samsung,exynos5250-pmu" - for Exynos5250 SoC,
+		   - "samsung,exynos5420-pmu" - for Exynos5420 SoC.
+		second value must be always "syscon".
+
+ - reg : offset and length of the register set.
+
+Example :
+pmu_system_controller: system-controller@10040000 {
+	compatible = "samsung,exynos5250-pmu", "syscon";
+	reg = <0x10040000 0x5000>;
+};

arch/arm/boot/dts/exynos5250.dtsi

@@ -167,6 +167,11 @@
 		interrupts = <0 47 0>;
 	};
 
+	pmu_system_controller: system-controller@10040000 {
+		compatible = "samsung,exynos5250-pmu", "syscon";
+		reg = <0x10040000 0x5000>;
+	};
+
 	watchdog {
 		clocks = <&clock 336>;
 		clock-names = "watchdog";

arch/arm/boot/dts/exynos5420.dtsi

@@ -613,6 +613,11 @@
 		samsung,power-domain = <&gsc_pd>;
 	};
 
+	pmu_system_controller: system-controller@10040000 {
+		compatible = "samsung,exynos5420-pmu", "syscon";
+		reg = <0x10040000 0x5000>;
+	};
+
 	tmu_cpu0: tmu@10060000 {
 		compatible = "samsung,exynos5420-tmu";
 		reg = <0x10060000 0x100>;