[SCSI] zfcp: Separate qdio attributes from zfcp_fsf_req

Split all qdio related attributes out of zfcp_fsf_req and put it in
new structure.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>