ARM: dts: Clean up exynos5250-smdk5250

Use the new style for referencing inherited nodes and use symbolic
names. Goal is the alignment of all exynos5250 based device trees
for comparison.
Signed-off-by: Andreas Faerber <afaerber@suse.de>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
[kgene.kim@samsung.com: rebased and squashed]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/boot/dts/exynos5250-snow.dts

@@ -226,6 +226,7 @@ panel: panel {
 		power-supply = <&fet6>;
 		backlight = <&backlight>;
 	};
+};
 
 &dp {
 	status = "okay";