Fix in-place-wiping failures when running on Oak

1. check machine type before copy files from lib/lib64
2. use which to find exec files instead of fixed path
3. add flashrom into tmp rootfs

BUG=chrome-os-partner:47253
TEST=Test in-place wiping on Oak and Paine.

Change-Id: Iff6ff66493e53c0ab8101f305b1f3db9e92b6ffe
Reviewed-on: https://chromium-review.googlesource.com/310603
Commit-Ready: Shun-Hsing Ou <shunhsingou@chromium.org>
Tested-by: Shun-Hsing Ou <shunhsingou@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
1 file changed