[SCSI] bfa: Fix Command Queue (CPE) full condition check and ack CPE interrupt.

Fixed the issue of not acknowledging the command queue
full-to-non-full interrupt.  Implemented separate acknowledging
functions for different ASIC and interrupt mode.

Fixed the case of missing CPE interrupt by always processing the
pending requests in the completion path.

Signed-off-by: Krishna Gudipati <kgudipat@brocade.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>