net: hns3: remove unused code of vmdq

Vmdq is not supported yet, the num_vmdq_vport is always 0,
it's a bit confusing when using the num_vport, so remove
these unused codes of vmdq.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
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>