amd-xgbe-phy: Print out the auto-negotiation method used

Add a netdev_info statement detailing whether auto-negotiation was
completed through parallel detection or through the auto-negotiation
protocol.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>