net: mvpp2: Add 2.5GBaseT support

The PPv2 controller is able to support 2.5G speeds, allowing to use
2.5GBASET in conjunction with PHYs that use 2500BASEX as their MII
interface when using this mode.
Signed-off-by: NMaxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c

@@ -4403,6 +4403,7 @@ static void mvpp2_phylink_validate(struct net_device *dev,
 	case PHY_INTERFACE_MODE_2500BASEX:
 		phylink_set(mask, 1000baseT_Full);
 		phylink_set(mask, 1000baseX_Full);
+		phylink_set(mask, 2500baseT_Full);
 		phylink_set(mask, 2500baseX_Full);
 		break;
 	default: