ARM: dts: Update display clock frequency for Origen-4412

As per the timing information for supported panel, the value should
be between 47.2 MHz to 47.9 MHz for 60Hz refresh rate.

Total horizontal pixels = 1024 (x-res) + 80 (margin) + 48 (hsync) = 1152
Total vertical pixels = 600 (y-res) + 80 (margin) + 3 (vsync) = 683

Target pixel clock rate for refresh rate @60 Hz
	= 1152 * 683 * 60 = 47208960 Hz ~ 47.5 MHz
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

arch/arm/boot/dts/exynos4412-origen.dts

@@ -159,7 +159,7 @@
 	display-timings {
 		native-mode = <&timing0>;
 		timing0: timing {
-			clock-frequency = <50000>;
+			clock-frequency = <47500000>;
 			hactive = <1024>;
 			vactive = <600>;
 			hfront-porch = <64>;