mana: add lro and tso stat counters
Add a few stat counters for tso and lro.
Approved by: re (gjb)
Sponsored by: Microsoft
(cherry picked from commit b167e449c8db01f082691503fb5c1255ad5750eb)
(cherry picked from commit a72a0af8194effa5f7e7a88d09673ed798819e88)