Add rt-tests package.

BUG=b:211523913
TEST=compiled on x86, arm-generic

Change-Id: Icce67f62588d9fab501782232adbe162f09661a6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/3350301
Tested-by: Eddy Hsu <eddyhsu@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Chih-Yang Hsia <paulhsia@chromium.org>
Commit-Queue: Eddy Hsu <eddyhsu@chromium.org>
6 files changed