ARM: dts: Add syscon-{reboot, poweroff} nodes for exynos4

This patch adds syscon-{reboot, poweroff} nodes to allow the
generic syscon-{reboot, poweroff} driver to reset/poweroff exynos4 SoC.

Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

arch/arm/boot/dts/exynos4.dtsi

@@ -158,6 +158,20 @@
 		interrupt-parent = <&gic>;
 	};
 
+	poweroff: syscon-poweroff {
+		compatible = "syscon-poweroff";
+		regmap = <&pmu_system_controller>;
+		offset = <0x330C>; /* PS_HOLD_CONTROL */
+		mask = <0x5200>; /* reset value */
+	};
+
+	reboot: syscon-reboot {
+		compatible = "syscon-reboot";
+		regmap = <&pmu_system_controller>;
+		offset = <0x0400>; /* SWRESET */
+		mask = <0x1>;
+	};
+
 	dsi_0: dsi@11C80000 {
 		compatible = "samsung,exynos4210-mipi-dsi";
 		reg = <0x11C80000 0x10000>;