if_xname, if_dname, and if_dunit. if_xname is the name of the interface
and if_dname/unit are the driver name and instance.
This change paves the way for interface renaming and enhanced pseudo
device creation and configuration symantics.
Approved By: re (in principle)
Reviewed By: njl, imp
Tested On: i386, amd64, sparc64
Obtained From: NetBSD (if_xname)
it attaches to all existing NATM network interfaces in the system
and creates a HARP physical interface for each of them. This allows
us to use the same set of ATM drivers for all ATM stuff. It is
possible to use the same interface for HARP, NATM and netgraph at the
same time.