qla2xxx: Remove SRR code

During initial implementation, tape support was included but not
enabled by default on target. So far, we don't see any target
customer requesting this support. Since this code is not being
used actively, we want to remove it and we will add back if there
are any request in future for SRR support.

Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Giridhar Malavali <giridhar.malavali@cavium.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>