cft: move servod to common-builder, but not enabled

no ebuild yet, so don't turn it on. also remove util.sh as this was the
last dep on it (I think)

BUG=None
TEST=cq

Change-Id: Iece2c324ae200ff014fff97cf0606fff13f0e445
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/3647005
Reviewed-by: Sergey Frolov <sfrolov@google.com>
Commit-Queue: Derek Beckett <dbeckett@chromium.org>
Reviewed-by: Seewai Fu <seewaifu@google.com>
Reviewed-by: Deniz Kara <denizkara@google.com>
Tested-by: Derek Beckett <dbeckett@chromium.org>