net: hns3: add support ethtool extended link state

In order to know the reason of link up failure, add supporting ethtool
extended link state. Driver reads the link status code from firmware if
in link down state and converts it to ethtool extended link state.

Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>