video: Drop references to CONFIG_VIDEO et al

Drop the Kconfigs which are not used and all references to them. In
particular, this drops CONFIG_VIDEO to avoid confusion and allow us to
eventually rename CONFIG_DM_VIDEO to CONFIG_VIDEO.

Also drop the prototype for video_get_info_str() which is no-longer used.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Jason Liu <jason.hui.liu@nxp.com>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 25c9fde..1d84012 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1786,7 +1786,7 @@
 
 config CMD_CLS
 	bool "Enable clear screen command 'cls'"
-	depends on CFB_CONSOLE || DM_VIDEO || LCD || VIDEO
+	depends on DM_VIDEO || LCD || VIDEO
 	default y if LCD
 	help
 	  Enable the 'cls' command which clears the screen contents