net: hns3: add support to update flow control settings after autoneg

net: hns3: add support to update flow control settings after autoneg

BugLink: http://bugs.launchpad.net/bugs/1756097
When auto-negotiation is enabled, the MAC flow control settings is
based on the flow control negotiation result. And it should be configured
after a valid link has been established. This patch adds support to update
flow control settings after auto-negotiation has completed.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 1770a7a3aeb23c0a1232486c8c4f50964725de46)
Signed-off-by: Manoj Iyer <manoj.iyer@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>