enetc: disable EEE autoneg by default

The EEE support has not been enabled on ENETC, but it may connect
to a PHY which supports EEE and advertises EEE by default, while
its link partner also advertises EEE. If this happens, the PHY enters
low power mode when the traffic rate is low and causes packet loss.
This patch disables EEE advertisement by default for any PHY that
ENETC connects to, to prevent the above unwanted outcome.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>