cxgb4: skip TX and RX payload regions in memory dumps

Use meminfo to identify TX and RX payload regions and skip them in
collection of EDC, MC, and HMA.

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>