abuild: Write XML/JUnit files per board

Write them per-board and merge them after everything is done.
This prepares for build parallelization.

Change-Id: Ia4e7ce03473bcf8861fb9ae06e9c1270292401ac
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/407
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed