net: sfp: remove incomplete 100BASE-FX and 100BASE-LX support

The 100BASE-FX and 100BASE-LX support assumes a PHY is present; this
is probably an incorrect assumption. In any case, sfp_parse_support()
will fail such a module. Let's stop pretending we support these
modules.

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