This temporary workaround is provided with the understanding that the 
following restrictions must be met or there may be unexpected behavior
and/or unintended operations to storage devices. Ideally applications 
should be recoded to properly use V5's multipathing environment and 
much larger B/T/L name space.

      - The system has no more than 64 SCSI buses, 8 targets
        per bus, and 8 luns per target.
      - The system has no Fibre Channel devices present.
      - The system has no SCSI-3 devices present.
      - The system has no KZPDC (Smart Array 5300) present.
      - There should be no more than one path to any storage
        device on the system.
      - The storage cables are never changed on the system.
      - No storage devices are to be hot swapped on the system.

This patch adds a hidden sysconfigtab variable, cam_limited_uagt_minor_nums,
which defaults to 0 for normal behavior.  Setting this to 1 allows
the user agent only 64 simultaneous opens maximum, but in doing
so, leaves bits <19:6> with a valid minor number.

