abuild: Add option of starting with an existing defconfig file

We want to start testing builds with additional Kconfig options to try
to get more coverage.  This will allow us to enable various options to
test without having to add each individual option to the abuild script.

Change-Id: I9bb2bb6f38589e3bcc1282dc4cad51cf6f5149aa
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/14016
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
1 file changed