lantiq: dts: assign the GPHY LED pins to the Ethernet controller node

lantiq: dts: assign the GPHY LED pins to the Ethernet controller node

Assign the GPHY LED pins to the Ethernet controller node instead of
using pin hogging (where pins are assigned to the pin controller).
This is the preferred way of assigning pins upstream.

Signed-off-by: Martin Blumenstingl <[email protected]>