net: hns3: add support for user-def data of flow director

For DEVICE_VERSION_V3, the hardware supports to match specified
data in the specified offset of packet payload. Each layer can
have one offset, and can't be masked when configure flow director
rule by ethtool command. The layer is selected based on the
flow-type, ether for L2, ip4/ipv6 for L3, and tcp4/tcp6/udp4/udp6
for L4. For example, tcp4/tcp6/udp4/udp6 rules share the same
user-def offset, but each rule can have its own user-def value.

For the user-def field of ethtool -N/U command is 64 bits long.
The bit 0~15 is used for user-def value, and bit 32~47 for user-def
offset in HNS3 driver.

Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>