scsi: qla2xxx: Limit interrupt vectors to number of CPUs

Driver created too many QPairs(126) with 28xx adapter.  Limit to the number
of CPUs to minimize wasted resources.

Link: https://lore.kernel.org/r/20201202132312.19966-4-njavali@marvell.com


Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>