iavf: Support Ethernet Type Flow Director filters

Support the addition and deletion of Ethernet filters.

Supported fields are: proto
Supported flow-types are: ether

Example usage:
ethtool -N ens787f0v0 flow-type ether proto 0x8863 action 6
ethtool -N ens787f0v0 flow-type ether proto 0x8864 action 7

Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Tested-by: Chen Bo <BoX.C.Chen@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>