net: hns: modify table index to get mac entry

Big-endian is not supported by the current definition of table index to get
mac entry. It needs to be modified to support both Little-endian
and Big-endian.

Signed-off-by: Qianqian Xie <xieqianqian@huawei.com>
Reviewed-by: Yisen Zhuang <yisen.zhuang@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>