cxgb4: collect hardware misc dumps

Collect path mtu, PM stats, TP clock info, congestion control, and VPD
data dumps.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>