video: move MXS to Kconfig

Move CONFIG_VIDEO_MXS from board headers to Kconfig
and drop it from obsolete cfb_console driver.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index b1f8a9c..9f789a6 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -648,6 +648,12 @@
 
 source "drivers/video/imx/Kconfig"
 
+config VIDEO_MXS
+	bool "Enable video support on i.MX28/i.MX6UL/i.MX7 SoCs"
+	depends on DM_VIDEO
+	help
+	  Enable framebuffer driver for i.MX28/i.MX6UL/i.MX7 processors
+
 config VIDEO_NX
 	bool "Enable video support on Nexell SoC"
 	depends on ARCH_S5P6818 || ARCH_S5P4418