ipu_common: Do not hardcode the ipu_clk frequency

Do not hardcode the ipu_clk frequency and let the board file pass this value.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/include/configs/mx51evk.h b/include/configs/mx51evk.h
index c3f4521..6af5ed7 100644
--- a/include/configs/mx51evk.h
+++ b/include/configs/mx51evk.h
@@ -133,6 +133,7 @@
 #define CONFIG_SPLASH_SCREEN
 #define CONFIG_BMP_16BPP
 #define CONFIG_VIDEO_LOGO
+#define CONFIG_IPUV3_CLK	133000000
 
 /* allow to overwrite serial and ethaddr */
 #define CONFIG_ENV_OVERWRITE