factory_test_tools: add display_geometry for ARM platforms

There is no EDID driver on ARM, and usually the screen size is already hard
coded in ARM board configuartion; so in hardware component probing, we trust the
frame buffer geometry data.

BUG=chromium-os:15119
TEST=./gft_hwcomp.py; # seeing 1YYYxZZZ on some ARM platforms.

Change-Id: Id84999227c92dd2462c610e265c93f42670828c9
Cherry-Picked: http://gerrit.chromium.org/gerrit/595
Reviewed-on: http://gerrit.chromium.org/gerrit/674
Reviewed-by: Rong Chang <rongchang@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
1 file changed