hinic: add vxlan segmentation and cs offload support

Add NETIF_F_GSO_UDP_TUNNEL and NETIF_F_GSO_UDP_TUNNEL_CSUM features
to support vxlan segmentation and checksum offload. Ipip and ipv6
tunnel packets are regarded as non-tunnel pkt for hw and as for other
type of tunnel pkts, checksum offload is disabled.

Signed-off-by: Luo bin <luobin9@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>