x86: video: Allow coreboot video to be used on any x86 board

When booting from coreboot we need this driver for the video to work.
Update the driver to be usable on any board.

The driver disables itself if it sees that is not booted from coreboot.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 667157c..63ae2ba 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -241,7 +241,7 @@
 
 config VIDEO_COREBOOT
 	bool "Enable coreboot framebuffer driver support"
-	depends on X86 && SYS_COREBOOT
+	depends on X86
 	help
 	  Turn on this option to enable a framebuffer driver when U-Boot is
 	  loaded by coreboot where the graphics device is configured by