Tg3 has a place to store stats, but doesn't really use it.  This patch
modifies the driver so that stats are saved across chip resets and gets
cleared across close / open calls.
Signed-off-by: NMatt Carlson <mcarlson@broadcom.com>
Reviewed-by: NMichael Chan <mchan@broadcom.com>
Reviewed-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>