Add option for "timeless" builds

Builds with BUILD_TIMELESS=1 shall always give a bit identical output
for stable inputs. This should help verifying that resulting rom files
stay the same across commits that shouldn't change the outcome.

To be useful for builds that rely on 3rdparty/arm-trusted-firmware,
this needs a similar change there.

Change-Id: Ia0a22e3e79fbd0abbd2a9071ecbeef6541787a08
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/13412
Tested-by: build bot (Jenkins)
Reviewed-by: Damien Zammit <damien@zamaudio.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2 files changed