scsi: NCR5380: Handle BUS FREE during reselection

The X3T9.2 specification (draft) says, under "6.1.4.2 RESELECTION time-out
procedure", that a target may assert RST or go to BUS FREE phase if the
initiator does not respond within 200 us. Something like this has been
observed with AztecMonster II target. When it happens, all we can do is wait
for the target to try again.

Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>