openwrt: Use go.chromiumos.org as base package

Other projects are using go.chromiumos.org as the base package name.
This project should use it too to be consistent, so this refactors
it to.

BUG=b:282831694
TEST=successfully built cros_openwrt_image_builder

Change-Id: Ieea9934c079fb8983fe65154b08a5867b289fc9b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/4546778
Reviewed-by: Billy Zhao <billyzhao@chromium.org>
Commit-Queue: Jared Bennett <jaredbennett@google.com>
Tested-by: Jared Bennett <jaredbennett@google.com>
11 files changed