net: sfp: add some quirks for GPON modules

Marc Micalizzi reports that Huawei MA5671A and Alcatel/Lucent G-010S-P
modules are capable of 2500base-X, but incorrectly report their
capabilities in the EEPROM.  It seems rather common that GPON modules
mis-report.

Let's fix these modules by adding some quirks.

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