sungem: improve ethtool output with internal pcs and serdes

From: Hermann Lauer <Hermann.Lauer@iwr.uni-heidelberg.de>

Attached is a patch which improves the output of ethtool (see below)
to some sensefull values with a sungem fibre card which uses the
sungem interal pcs connected to a serdes chip. The seriallink case in
the driver is untouched.

Most values are hardcoded, because gigabit fibre autoneg is anyways
limited and the driver don't really support much at the moment with
that hardware.

Signed-off-by: David S. Miller <davem@davemloft.net>