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/arch/x86/Kconfig b/arch/x86/Kconfig
index 7e86c6a..a2da080 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -703,7 +703,7 @@
 
 config VIDEO_FSP
 	bool "Enable FSP framebuffer driver support"
-	depends on HAVE_VBT && DM_VIDEO
+	depends on HAVE_VBT && VIDEO
 	help
 	  Turn on this option to enable a framebuffer driver when U-Boot is
 	  using Video BIOS Table (VBT) image for FSP firmware to initialize