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/drivers/video/imx/Kconfig b/drivers/video/imx/Kconfig
index 78eb0f2..afe950b 100644
--- a/drivers/video/imx/Kconfig
+++ b/drivers/video/imx/Kconfig
@@ -1,7 +1,7 @@
 
 config VIDEO_IPUV3
 	bool "i.MX IPUv3 Core video support"
-	depends on DM_VIDEO && (MX5 || MX6)
+	depends on VIDEO && (MX5 || MX6)
 	help
 	  This enables framebuffer driver for i.MX processors working
 	  on the IPUv3(Image Processing Unit) internal graphic processor.