ARM: dts: exynos: Add SCU device node to exynos4.dtsi

Exynos4 like other Cortex-A9 SoC's has a Snoop Control Unit(SCU)
and its SFR are used during SMP boot and S2R. Add SCU node to the device tree.
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm/boot/dts/exynos4.dtsi

@@ -78,6 +78,11 @@ chipid@10000000 {
 		reg = <0x10000000 0x100>;
 	};
 
+	scu: snoop-control-unit@10500000 {
+		compatible = "arm,cortex-a9-scu";
+		reg = <0x10500000 0x2000>;
+	};
+
 	memory-controller@12570000 {
 		compatible = "samsung,exynos4210-srom";
 		reg = <0x12570000 0x14>;