qla2xxx: Move atioq to a different lock to reduce lock contention

99% of the time the ATIOQ has SCSI command.  The other 1% of time
is something else.  Most of the time this interrupt does not need
to hold the hardware_lock.  We're moving the ATIO interrupt thread
to a different lock to reduce lock contention.

Signed-off-by: Quinn Tran <quinn.tran@qlogic.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>