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/configs/nokia_rx51_defconfig b/configs/nokia_rx51_defconfig
index d24a8e7..8e55069 100644
--- a/configs/nokia_rx51_defconfig
+++ b/configs/nokia_rx51_defconfig
@@ -65,7 +65,7 @@
 CONFIG_USB=y
 CONFIG_USB_MUSB_UDC=y
 CONFIG_USB_OMAP3=y
-CONFIG_DM_VIDEO=y
+CONFIG_VIDEO=y
 CONFIG_VIDEO_LOGO=y
 # CONFIG_VIDEO_BPP8 is not set
 # CONFIG_VIDEO_BPP32 is not set