net: dsa: felix: Set USXGMII link based on BMSR, not LPA

At least some PHYs (AQR412) don't advertise copper-side link status
during system side AN.

So remove this duplicate assignment to pcs->link and rely on the
previous one for link state: the local indication from the MAC PCS.

Fixes: bdeced75 ("net: dsa: felix: Add PCS operations for PHYLINK")
Signed-off-by: Alex Marginean <alexandru.marginean@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>