ARM: EXYNOS: Add cpu-offset property in gic device tree node

Commit db0d4db22a78 ('ARM: gic: allow GIC to support non-banked setups)
requires a cpu-offset property to be specified for non-banked gic
controllers, which is the case for Exynos4.

Reported-and-Tested-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/boot/dts/exynos4210.dtsi

@@ -29,6 +29,7 @@
 		compatible = "arm,cortex-a9-gic";
 		#interrupt-cells = <3>;
 		interrupt-controller;
+		cpu-offset = <0x8000>;
 		reg = <0x10490000 0x1000>, <0x10480000 0x100>;
 	};