the adapter consumes two tids for every ipv6 offload
connection be it active or passive, calculate tid usage
count accordingly.

Also change the signatures of relevant functions to get
the address family.
Signed-off-by: NRizwan Ansari <rizwana@chelsio.com>
Signed-off-by: NVarun Prakash <varun@chelsio.com>
Signed-off-by: NGanesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>