Revert the image size increasing for abuild. It breaks more boards than

Revert the image size increasing for abuild. It breaks more boards than
it fixes. It seems many of the other boards run out of space for the
payload.

Thus, this patch only increases the image size for the three boards

 - tyan/s2912
 - nvidia/l1_2pvv
 - gigabyte/m57sli

by adding a custom Config-abuild.lb file for each of them.

Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2618 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1