cxgb4/cxgbvf: Handle 32-bit fw port capabilities

Implement new 32-bit Firmware Port Capabilities in order to
handle new speeds which couldn't be represented in the old 16-bit
Firmware Port Capabilities values.

Based on the original work of Casey Leedom <leedom@chelsio.com>

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