scsi: 53c700: move bus reset to host reset

bus reset always returns SUCCESS, meaning host reset was never
tested. At the same time the only difference to the HBA is a missing
call to NCR_700_chip_reset().  So add the missing call to bus reset,
drop host reset, and move bus reset to host reset.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>