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/mx6sabresd_defconfig b/configs/mx6sabresd_defconfig
index 5db8182..f7ef8ed 100644
--- a/configs/mx6sabresd_defconfig
+++ b/configs/mx6sabresd_defconfig
@@ -117,7 +117,7 @@
 CONFIG_USB_GADGET_VENDOR_NUM=0x0525
 CONFIG_USB_GADGET_PRODUCT_NUM=0xa4a5
 CONFIG_CI_UDC=y
-CONFIG_DM_VIDEO=y
+CONFIG_VIDEO=y
 CONFIG_VIDEO_LOGO=y
 # CONFIG_VIDEO_BPP8 is not set
 # CONFIG_VIDEO_BPP32 is not set