RDMA/nes: Correct MAX TSO frags value

Use correct define for max TSO fragments.

Signed-off-by: Bob Sharp <bsharp@neteffect.com>
Signed-off-by: Sweta Bhatt <sweta.bhatt@einfochips.com>
Signed-off-by: Chien Tung <ctung@neteffect.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>