factory_reset: remove support for board specific reset script

We have unified the cut-off process into a common script for both
in-place wiping and reset shim. After resetting device, we shouldn't do
additional stuff. Remove the support for board specific reset script
to avoid unexpected behavior for factory reset.

BUG=chromium:544021
TEST=manually run reset shim on Chell

Change-Id: I5cc4a529fabb4fa0fe1babf78c7a397e0ea82df1
Reviewed-on: https://chromium-review.googlesource.com/407897
Commit-Ready: Shun-Hsing Ou <shunhsingou@chromium.org>
Tested-by: Shun-Hsing Ou <shunhsingou@chromium.org>
Reviewed-by: Ting Shen <phoenixshen@chromium.org>
1 file changed