The FEC capbility may be changed with port speed changes. Driver
needs to read the active FEC mode, and update FEC capability
when port speed changes.

Fixes: 7e6ec914 ("net: hns3: add support for FEC encoding control")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>