topo should create per-device UFM entries by default
In the original implementation of the UFM subsystem, UFM entries in topo showed up on a per-PCI function basis by default, but all of the multi-function device at the time (i40e) actually had UFMs shared between all devices. Instead, topo should default to create the UFM data on a per-device basis by default.
I considered adding UFM APIs to indicate this, but until we have devices that actually exist on a per-function basis, it didn't seem like there was much point to doing so. However, if a driver does declare one, then we will go ahead and it to the function when it isn't on function zero so at least it isn't lost.