net: hns3: remove some unused macros

There are some macros defined in hns3_enet.h, but not used in
anywhere.

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