Map bitband ACLs back to original peripheral adresses to detect overlap

- currently the ACL collision detection in uVisor does not take into account that a bitband-ACL might overlap with a peripheral-ACL for the same peripheral.
- ensure to mark peripherals corresponding to bitband-ACL as used
- still allow the same box to have both bitband ACL and peripheral ACL for the same peripherals

Start by locating uVisor's ACL collision-detection logic and the handling of bitband and peripheral ACLs. Trace how a bitband ACL identifies its original peripheral, then verify that the peripheral is marked used for overlap checks while the same box can retain both ACL types for that peripheral.

Written by the indexing model from the issue text.