scsi: qla2xxx: Add multiple queue pair functionality.

Replaced existing multiple queue functionality with framework
that allows for the creation of pairs of request and response queues,
either at start of day or dynamically.

Queue pair creation depend on module parameter "ql2xmqsupport",
which need to be enabled to create queue pair.

Signed-off-by: Sawan Chandak <sawan.chandak@cavium.com>
Signed-off-by: Michael Hernandez <michael.hernandez@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>