PCI: Migrate from BSF to BDF convention

[pearsonk]

Slot designation is a bit of a misnomer when referring to the addressing field, which is conventionally called Device in Domain:Bus:Device.Function notations.
Further, as it seems relevant, actual slot information can be pulled from DMI (type 9) with a lookup of the Designation for a matching Bus Address for the first Function of the device. Absence of a DMI entry would signify an internal PCI device not connected to an expansion slot.

[ffromani]

fixed by #252