3.0.75-1: fix some registration quirks related to the platform (#1651)

* fix some registration quirks related to the platform
- skip registration check for --support (RHIPLAT1-748)
- skip --unregister call, log message (RHIPLAT1-749)
- skip --register call, log message (RHIPLAT1-750)
- short-circuit --status, log message (RHIPLAT1-751)

* FLAKE

* move logging and checks to API functions. phase calls reg normally

* fix goof