Implement operations to set/get dump data via ethtool.  Also add
template header that precedes dump data, which helps in decoding
and extracting the dump data.
Signed-off-by: NRahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: NGanesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>