[SCSI] qla4xxx: Fix processing response queue during probe

Issue:
While booting with kdump kernel, driver receive IOCB interrupts
for which it is not ready which results in processing them
before init_firmware during driver probe

Fix:
Two steps solution
1. Make driver ready to process the interrupt before interupts
   handlers is registered.
2. Stop driver processing iocb interrupts if not generated as per
   firmware protocol i.e R2H bit set

Signed-off-by: Tej Parkash <tej.parkash@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>