net: hns3: remove some unused fields in struct hns3_nic_priv

Remove some fileds which defined in struct hns3_nic_priv,
but not used, and remove the related definition of struct
hns3_udp_tunnel and enum hns3_udp_tnl_type.

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