Patch merged into coreboot/master: arch/x86: avoid race condition on build.h

the following patch was just integrated into master:
commit ab355750fc444315bfecf4be2195a98eceaeacef
Author: Patrick Georgi 
Date:   Thu Oct 15 11:07:07 2015 +0200

arch/x86: avoid race condition on build.h

Change-Id: I15375ac1247b7cc8d80d910a767c7f3e67eb8739
    Signed-off-by: Patrick Georgi 
    Reviewed-on: http://review.coreboot.org/11904
    Tested-by: build bot (Jenkins)
    Reviewed-by: Paul Menzel 
    Reviewed-by: Nico Huber

See http://review.coreboot.org/11904 for details.

-gerrit