build system: Allow overriding the path to the futility binary

Change-Id: I84e68e8407149780769c3e6a1148c175e42d1025
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/14100
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed