ARM: dts: Add syscon phandle to the video-phy node for Exynos4

This is required to fix regression after introducing the PMU device
nodes required for the PMU driver modified in commit 14fc8b93
("ARM: EXYNOS: Add platform driver support for Exynos PMU").
This change is needed to make MIPI DSI displays and MIPI CSI-2
camera sensors working again on Exynos4 boards.
Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NKukjin Kim <kgene@kernel.org>

arch/arm/boot/dts/exynos4.dtsi

@@ -76,6 +76,7 @@
 		compatible = "samsung,s5pv210-mipi-video-phy";
 		reg = <0x10020710 8>;
 		#phy-cells = <1>;
+		syscon = <&pmu_system_controller>;
 	};
 
 	pd_mfc: mfc-power-domain@10023C40 {