Concomitant changes to code that prints driver/unit name: use dv_xname
and dv_unit, instead of doing pointer arithmetic on elements of the static
softc array.
Remove support for old config. The old-config "driver" structure
is still present, because the pmax non-MI SCSI driver needs it.
Merge some off Per Fogelstrom's changes for the Pica driver,
which uses the machine-independent SCSI code. This is #ifdef'ed
out until the DMA is fixed to work on Decstations, too.
97cf65df4a