Patch merged into coreboot/master: abuild: Allow disabling mainboards

the following patch was just integrated into master:
commit 3ac3c4ebac8700ba99f2fdaf745d3e6aa1056dca
Author: Patrick Georgi 
Date:   Tue Jul 14 20:20:13 2015 +0200

abuild: Allow disabling mainboards

There may be boards that shouldn't be built for one reason or another.
    Allow black-listing them by adding a file to the mainboard directory called
    'abuild.disabled'. It should contain the reason that is printed by abuild and
    also serves as documentation for users that want to know what's going on.

Change-Id: I78c3281a578e96ee40f6b101143d4f3763582350
    Signed-off-by: Patrick Georgi 
    Reviewed-on: http://review.coreboot.org/10917
    Tested-by: build bot (Jenkins)
    Reviewed-by: Aaron Durbin

See http://review.coreboot.org/10917 for details.

-gerrit