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/vision2.h b/include/configs/vision2.h
index 919f5ce..0ed53d2 100644
--- a/include/configs/vision2.h
+++ b/include/configs/vision2.h
@@ -219,5 +219,6 @@
 #define CONFIG_SPLASH_SCREEN
 #define CONFIG_CMD_BMP
 #define CONFIG_BMP_16BPP
+#define CONFIG_IPUV3_CLK	133000000
 
 #endif				/* __CONFIG_H */