firmware-updater: Detect legacy flashrom program.

When updating with programs from old system, we must detect and use the old
"-p internal:bus=*" syntax.

BUG=chrome-os-partner:20261
TEST=manually: remove the flashrom from firmware updater bundle and see flashrom
     invoked with "-p internal:bus=*" param.
CQ-DEPEND=CL:58933

Change-Id: I2669d50bab48d18bb8045d6f2d8b278ed5c2341f
Reviewed-on: https://gerrit.chromium.org/gerrit/58950
Tested-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Commit-Queue: Doug Anderson <dianders@chromium.org>
1 file changed