net: hns3: support wake on lan configuration and query

The HNS3 driver supports Wake-on-LAN, which can wake up
the server from power off state to power on state by magic
packet or magic security packet.

ChangeLog:
v1->v2:
Deleted the debugfs function that overlaps with the ethtool function
from suggestion of Andrew Lunn.

v2->v3:
Return the wol configuration stored in driver,
suggested by Alexander H Duyck.

v3->v4:
Add a helper to go from netdev to the local struct,
suggested by Simon Horman and Jakub Kicinski.

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Hao Lan <lanhao@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>