Fix: BMDA AP access decoding

[dragonmux]

Detailed description

This PR addresses an issue found with @desertsagebrush's help where the AP for a request would always be decoded for DEBUG_PROTO display as being AP 1.

This PR also addresses the same function's (decode_access()) handling of the AP/!DP bit in the address value passed to it.

Your checklist for this pull request

• I've read the Code of Conduct
• I've read the guidelines for contributing to this repository
• It builds for hardware native (make PROBE_HOST=native)
• It builds as BMDA (make PROBE_HOST=hosted)
• I've tested it to the best of my ability
• My commit messages provide a useful short description of what the commits do

Closing issues

[esden]

LGTM