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/ge_bx50v3_defconfig b/configs/ge_bx50v3_defconfig
index 09a8432..52d9569 100644
--- a/configs/ge_bx50v3_defconfig
+++ b/configs/ge_bx50v3_defconfig
@@ -93,7 +93,7 @@
 CONFIG_MXC_SPI=y
 CONFIG_SYSRESET=y
 CONFIG_SYSRESET_WATCHDOG=y
-CONFIG_DM_VIDEO=y
+CONFIG_VIDEO=y
 # CONFIG_VIDEO_BPP8 is not set
 # CONFIG_VIDEO_BPP32 is not set
 CONFIG_SYS_WHITE_ON_BLACK=y