amd-xgbe-phy: Sync PCS and PHY modes after reset

This patch adds support to sync the states of the PCS and the PHY
after a reset is performed.  If the PCS and the PHY are not in the
same state after reset an extra mode change would be performed. This
extra mode change might not be needed if the PCS and the PHY are
synced up after reset.

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