net: hns3: add support for imp-controlled PHYs

IMP(Intelligent Management Processor) firmware add a new feature
to take control of PHYs for some new devices, PF driver adds
support for this feature.

Driver queries device's capability to check whether IMP supports
this feature, it will tell IMP to enable this feature by firmware
compatible command if it is supported.

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