Notify the hub about category registration

:Release Notes:

:Detailed Notes:

:Testing Performed:
make check && make test

:QA Notes:

:Issues Addressed:
[BHV-1252] Add 2-step ls2 bus registration APIs

Open-webOS-DCO-1.0-Signed-off-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>

Change-Id: I456e98a69795ecf72b6b664fe80eceb01827beba
Reviewed-on: https://g2g.palm.com/5271
Reviewed-by: DCO Verification
Reviewed-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>
Tested-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>
Reviewed-by: Alekseyev Oleksandr <alekseyev.oleksandr@lge.com>
Reviewed-by: Nikolay Orliuk <nikolay.orliuk@lge.com>