soc/amd/stoney: Allow alternative placement for AMD FW directory

Allow the AMD FW directory to be placed at one of the alternative
locations within the ROM.

BUG=b:65484600
TEST=Assign PSP firmware location, build & test.

Change-Id: I9c95b9805c60ab6204750f7929049c7382e0c6cd
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/21456
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
2 files changed