Patch merged into coreboot/master: abuild: avoid hanging in oldconfig for parallel builds

the following patch was just integrated into master:
commit 1d915cae2b946561515c1309000b284f08fb8b80
Author: Patrick Georgi 
Date:   Fri Jul 31 16:46:55 2015 +0200

abuild: avoid hanging in oldconfig for parallel builds

oldconfig may wait for some input. Since we don't care while building tools,
    just provide something.

Change-Id: I1c6f1b46957301886a7645cfb6c6bd264437aa7e
    Signed-off-by: Patrick Georgi 
    Reviewed-on: http://review.coreboot.org/11094
    Tested-by: build bot (Jenkins)
    Reviewed-by: Stefan Reinauer

See http://review.coreboot.org/11094 for details.

-gerrit