tlan: Enable activity LED on Olicom OC-2325 and OC-2326

Olicom OC-2325 and OC-2326 ethernet cards have an activity LED but it does not
work with tlan driver as it's not enabled. Enable it.
Tested with OC-2326.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: David S. Miller <davem@davemloft.net>