amd-xgbe: propagate the correct speed and duplex status

xgbe_get_link_ksettings() does not propagate correct speed and duplex
information to ethtool during cable unplug. Due to which ethtool reports
incorrect values for speed and duplex.

Address this by propagating correct information.

Fixes: 7c12aa08

 ("amd-xgbe: Move the PHY support into amd-xgbe")
Acked-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>