pkgbase: Move tr(1) to runtime

Since f7d16a627efa ("certctl: Convert line endings before inspecting files.")
certctl is using tr(1). Add it to FreeBSD-runtime so we can have certctl working
without having the bloated FreeBSD-utilities.

Sponsored by: Beckhoff Automation GmbH & Co. KG

(cherry picked from commit 0fb9d5786bff57a7d5b2056fdbc1baaec9406885)