dt-bindings: net: Updated micrel,led-mode for LAN8814 PHY

Enable led-mode configuration for LAN8814 phy

Signed-off-by: Divya Koppera <Divya.Koppera@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>