Porting ethernet support for Pi 3B+ to 8

[Mayuresh <mayuresh%acm.org@localhost>]

I am stuck with a Pi 3B+ in a situation where I can't use -current due to
not being able to compile some packages and not being able to use -8 due
to lack of ethernet support.

Is it possible to take ethernet support code from -current and back port
it to -8? I am not an expert in kernel code, but can give it a try with
support from the list.

Mayuresh