add patches for sx763 support

Add patches to support sx763 on lantiq target.

For now leds don't work, also wifi interface gets mac address from eeprom, and since it is same on all devices it has to be set in config to read it from lan mac.
I see that you configure specific MAC addresses here that are read from uboot environment? What happens if you want to pre-configure the node so that uci-defaults are not applied?