[autotest] Log servo version at initialization

For debug purposes:  When initializing servo, log the servo
(hardware) version returned by servod.

BUG=None
TEST=run a servo test using test_that with this change present

Change-Id: I1abe8d79ff9f6915a33075511055f6aeee51ab79
Reviewed-on: https://chromium-review.googlesource.com/216283
Commit-Queue: Richard Barnette <jrbarnette@chromium.org>
Tested-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: Yusuf Mohsinally <mohsinally@chromium.org>
1 file changed