Drop VGA_BRIDGE_SETUP config option

It defaults to true, and isn't disabled anywhere in the tree.
I also couldn't think of a case where it's actually useful.

Change-Id: I126a47625d5294f3cfff225629f2a948a83c9b7e
Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Reviewed-on: http://review.coreboot.org/1250
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
3 files changed