net: sfp: derive interface mode from ethtool link modes

We don't need the EEPROM ID to derive the phy interface mode as we can
derive it merely from the ethtool link modes.  Remove the EEPROM ID
argument to sfp_select_interface().

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>