scsi: remove NCR_Q720 driver

The NCR QUAD 720 SCSI driver depends on microchannel support, but
microchannel support was removed from the kernel with commit bb8187d3


("MCA: delete all remaining traces of microchannel bus support.") over 6
years ago.

So zap the Q720 SCSI driver as well.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>