[SCSI] bnx2i: Fine tuned conn destroy and context destroy timeout values

Added variables to separate the fine tuned timeout values for
connection destroy and context destroy for both 1g and 10g devices.

v2: Extended the 5771X disconnect timeout from 10s to 20s as the firmware
has a retransmission timeout of 16s.  This fixes one of the iscsi_endpoint
leak issues when the target is slow or non-responsive to our TCP FIN.

Signed-off-by: Eddie Wai <eddie.wai@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Reviewed-by: Benjamin Li <benli@broadcom.com>
Acked-by: Anil Veerabhadrappa <anilgv@broadcom.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>