ethernet: use device api

Use device API to control DUT

BUG=chromium:557573
TEST=manual

Change-Id: I7972dad006e3484563ac54eaee366509ba3eca60
Reviewed-on: https://chromium-review.googlesource.com/364412
Commit-Ready: Wei-Han Chen <stimim@chromium.org>
Tested-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Chih-Yu Huang <akahuang@chromium.org>
1 file changed