drivers/net/mlx4: Adjust constant

The values in the advertising field are typically ADVERTISED_xxx, not
SUPPORTED_xxx.  Both SUPPORTED_10000baseT_Full and
ADVERTISED_1000baseT_Full have the same value.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
struct ethtool_cmd E;
@@
*E.advertising = SUPPORTED_10000baseT_Full
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>