Standardize nvme SGL segment count

Standardize default SGL segment count for nvme target and initiator

The driver needs to make them the same for clarity.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>