emerald: Switch to unified sepolicy repository and drop non-required revisions

Description

This MR drops non-required revisions to follow the global scheme

Issue(s)

• https://gitlab.e.foundation/e/devices/backlog/-/issues/144

Test environment

Not applicable

Test procedures

Ensure the branches have the global revision present.

Technical details

None available

Screenshots

None available

Checklist

• Self-review