net: dsa: felix: Handle PAUSE RX regardless of AN result

Flow control is used with 2500Base-X and AQR PHYs to do rate adaptation
between line side 100/1000 links and MAC running at 2.5G.

This is independent of the flow control configuration settled on line
side though AN.

In general, allowing the MAC to handle flow control even if not
negotiated with the link partner should not be a problem, so the patch
just enables it in all cases.

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>