net: hns3: net: hns3: add querying and setting fec off mode from firmware

For some new devices, the FEC mode can not be set to OFF in speed 200G.
In order to flexibly adapt to all types of devices, driver queries
fec ability from firmware to decide whether OFF mode can be supported.

Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>