mana: fix tso parameters and set hwassist bits

The parameters for tso on mana were not set correctly. Also the
hwassist bits were not set. These two cause tso on mana not work.
Fixed the issues and make tso working on mana.

Tested by: whu
MFC after: 3 days
Sponsored by: Microsoft

(cherry picked from commit 643fd7b4bc57de87ddfeb75a8f0bdb27dbb8c3ce)