scsi: qla2xxx: remove irq_affinity_notifier

Now that qla2xxx uses the IRQ layer affinity assignment, affinity won't
change over the life time of a device and the notifiers are useless.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>