Have sio return BIS_PROBE_DEFAULT like all the other drivers in the tree...  John Baldwin noted that sio might pass values between probe and attach via softc.  It appears that sio does leave the hardware in a known state after probing, so other drivers that try to probe might leave it in a worse state.  It doesn't seem to pass any data in softc, however, that I could find...  I think we should not be probing for anything but nonPnP isa, but that's a change for another day.
Have sio return BIS_PROBE_DEFAULT like all the other drivers in the
tree...  John Baldwin noted that sio might pass values between probe
and attach via softc.  It appears that sio does leave the hardware in
a known state after probing, so other drivers that try to probe might
leave it in a worse state.  It doesn't seem to pass any data in softc,
however, that I could find...  I think we should not be probing for
anything but nonPnP isa, but that's a change for another day.

Submitted by: Frank Behrens
PR: 87845

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