staging: et131x: Remove private adapter->linkspeed and use phydev->speed instead

The phy device keeps a note of the link speed, so use that value instead of the driver private one.

Also use the phydev defines for link speeds, and remove the driver private ones.

adapter->hw_errs was never used, even in the vendor driver, so remove that too.

Signed-off-by: Mark Einon <mark.einon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>