amd-xgbe-phy: Provide support for auto-negotiation timeout

Currently, there is no interrupt code that indicates auto-negotiation
has timed out. If the auto-negotiation has timed out then the start of
a new auto-negotiation will begin again with a new base page being
received. The state machine could be in a state that is not expecting
this interrupt code which results in an error during auto-negotiation.

Update the code to timestamp when the auto-negotiation starts.  Should
another page received interrupt code occur before auto-negotiation has
completed but after the auto-negotiation timeout, then reset the state
machine to allow the auto-negotiation to continue.

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