for the harp(4) pseudo driver and for loadable native HARP drivers
(like hfa_pci).
To use harp(4) the rc variable natm_interfaces must be set to the
list of NATM interfaces to be used for HARP. These interfaces
will be brought up with ifconfig and the harp(4) will be loaded.
To use loadable native HARP drivers atm_load must be set to
the list of drivers to load.
Reviewed by: mtm, gordon (partly)
33549ec7ad