Use bzip2 when making a tarball

Tarballs on download.flashrom.org are generally packaged using bzip2, so
we may as well be internally consistent.

Change-Id: Ib9fb1ea6d5994cd0285ce8db9675640fae992773
Signed-off-by: David Hendricks <dhendricks@fb.com>
Reviewed-on: https://review.coreboot.org/22116
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-on: https://review.coreboot.org/22335
1 file changed