[TG3]: MII => TP

This patch changes the PHY type reported through ethtool for copper
devices from MII to TP.  The latter is more accurate.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>