Add oldest Ralink MIPS SOC RT2880 support code. Target module have ic plus etherswitch ip175c. Also add etherswitch support code on rt driver.
This code relation D10295 review that is fdt away etherswitch patch.
This is dmesg.
https://gist.github.com/yamori813/ebb3147d78b6c375dfe12f782f6308f8