[SCSI] bfa: Modified the portstats get/clear logic

Modified the portstats get/clear logic for port physical/FCoE/QoS stats.
Added more stats to FC
Fixed some issues with FCoE stats collection.

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