net: phy: add 1000Base-X to phy settings table

Add the missing 1000Base-X entry to the phy settings table.  This was
not included because the original code could not cope with more than
32 bits of link mode mask.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>