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 was wrong about wifi mac, that one is read correctly from kernel command line, but lan mac is bugged out.
Interface driver should read it, but on lantiq afaik it can only read it from devices that have mac on specific mtd partition, so we should either use script to read it from uboot_env just like uci-defaults, or I could patch interface driver to configure it from kernel command line.