cxgb4: Don't disallow turning off auto-negotiation

For {1, 10, 40} Gb/s. Prohibiting turning off autonegotiation isn't anywhere
in the standard.
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c

@@ -629,10 +629,7 @@ static int set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 	if (cmd->autoneg == AUTONEG_DISABLE) {
 		cap = speed_to_caps(speed);
 
-		if (!(lc->supported & cap) ||
-		    (speed == 1000) ||
-		    (speed == 10000) ||
-		    (speed == 40000))
+		if (!(lc->supported & cap))
 			return -EINVAL;
 		lc->requested_speed = cap;
 		lc->advertising = 0;