i40e: Adds FCoE related code to i40e core driver

Adds FCoE specific code to existing i40e core driver to:-

1. have separate FCoE VSI with additional FCoE queues pairs.
2. have FCoE related hash defines.
3. have additional FCoE related stats code.
4. export and then re-use existing functions required by FCoE build.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Jack Morgan<jack.morgan@intel.com>
Signed-off-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>