entity manager configurations and dbus interfaces

[Brad Bishop]

Hi Ed

Will quote a comment from this EM review:

https://gerrit.openbmc-project.xyz/36702

> entity-manager was designed with the tenant that it config files have 
> no knowledge of dbus.

FWIW I had no idea this was the case.

> We've broken that a little with the inventory interfaces on the entity 
> as a short term patch to gain some compatibility, but its easy enough 
> to roll back in the future.

Interesting - so there is a vision here, but I have no idea what it is.  
Can you elaborate on how you envision inventory working if EM is not 
implementing the inventory dbus interfaces?

thx - brad