net: hns3: Fix for information of phydev lost problem when down/up

Function call of phy_connect_direct will reinitialize phydev. Some
information like advertising will be lost. Phy_connect_direct only
needs to be called once. And driver can run well. This patch adds
some functions to ensure that phy_connect_direct is called only once
to solve the information of phydev lost problem occurring when we stop
the net and open it again.

Fixes: 46a3df9f ("net: hns3: Add HNS3 Acceleration Engine & Compatibility Layer Support
Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>