imx: mx6: correct IPU clock

The CONFIG_IPUV3_CLK should be 264000000, to i.MX6DL, it should be
198000000.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Signed-off-by: Sandor Yu <sandor.yu@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Peter Robinson <pbrobinson@gmail.com>

include/configs/mx6sabre_common.h

@@ -225,7 +225,11 @@
 #define CONFIG_BMP_16BPP
 #define CONFIG_VIDEO_LOGO
 #define CONFIG_VIDEO_BMP_LOGO
-#define CONFIG_IPUV3_CLK 260000000
+#ifdef CONFIG_MX6DL
+#define CONFIG_IPUV3_CLK 198000000
+#else
+#define CONFIG_IPUV3_CLK 264000000
+#endif
 #define CONFIG_IMX_HDMI
 #define CONFIG_IMX_VIDEO_SKIP