video: Rename CONFIG_DM_VIDEO to CONFIG_VIDEO

Now that all the old code is gone, rename this option. Driver model
migration is now complete.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/tegra-common-post.h b/include/configs/tegra-common-post.h
index 823b5d6..4e20e1d 100644
--- a/include/configs/tegra-common-post.h
+++ b/include/configs/tegra-common-post.h
@@ -37,7 +37,7 @@
 #define STDIN_KBD_USB ""
 #endif
 
-#ifdef CONFIG_DM_VIDEO
+#ifdef CONFIG_VIDEO
 #define STDOUT_VIDEO ",vidconsole"
 #else
 #define STDOUT_VIDEO ""