net: hns3: Add support for rule add/delete for flow director

This patch adds support for add and delete rule by ethtool commands.
HNS3 driver supports several flow types, include ETHER_FLOW,
IP_USER_FLOW, TCP_V4_FLOW, UDP_V4_FLOW, SCTP_V4_FLOW, IPV6_USER_FLOW,
TCP_V6_FLOW, UDP_V6_FLOW and SCTP_V6_FLOW.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>