It's prone to problems if delay is cleared out for other than RGMII
modes. So lets set/clear the TX-delay in the config register only
if actually RGMII-like interface mode is requested. This only
concerns rtl8211f chips.
Signed-off-by: NSerge Semin <fancer.lancer@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>