mlxsw: spectrum: Indicate support for autonegotiation

The device supports link autonegotiation, so let the user know about it
by indicating support via ethtool ops.

Fixes: 56ade8fe ("mlxsw: spectrum: Add initial support for Spectrum ASIC")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -1417,7 +1417,8 @@ static int mlxsw_sp_port_get_settings(struct net_device *dev,
 
 	cmd->supported = mlxsw_sp_from_ptys_supported_port(eth_proto_cap) |
 			 mlxsw_sp_from_ptys_supported_link(eth_proto_cap) |
-			 SUPPORTED_Pause | SUPPORTED_Asym_Pause;
+			 SUPPORTED_Pause | SUPPORTED_Asym_Pause |
+			 SUPPORTED_Autoneg;
 	cmd->advertising = mlxsw_sp_from_ptys_advert_link(eth_proto_admin);
 	mlxsw_sp_from_ptys_speed_duplex(netif_carrier_ok(dev),
 					eth_proto_oper, cmd);