tg3: copy only needed fields from userspace-provided EEE data

The current code overwrites fields in tp->eee with unchecked data from
edata, e.g. the bitmap with supported modes. ethtool properly returns
the received data from get_eee() call, but we have no guarantee that
other users of the ioctl set_eee() interface behave properly too.
Therefore copy only fields which are actually needed.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>