This is the first part to implement flow steering. The communication
between ethtool and driver is done. User can use following commands
to display and set flows:

ethtool -n <netdev>
ethtool -N <netdev> flow-type ...
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20231117071114.10667-2-louis.peens@corigine.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>