Remove AppArmor docs

There are two AppArmor documents that have been carried over from the wiki
which both have issues:

- docs/security/apparmor.md
  - Describes apparmor profiles that no longer seem to be a part of Apertis
  - User session has signinficantly changed, no longer primarily using
    X.org

- docs/security/apparmor/d-bus.md
  - Discusses patches that are either fully integrated into Apertis or
    upstream by now
  - Some of the debugging tips no longer work
  - Discusses possible solutions to a D-Bus issue rather than stating
    implemented solution

These pages provide very little and contain lots of out-of-date
information. Remove them.