Currently, because they are so simple, we don't have makefile.inc files for i2c drivers. see serengeti_cheetah: driver-y += ../../../drivers/i2c/i2cmux/i2cmux.o
This is admittedly inconsistent, but it saves a lot of unnecessary makefile.inc stuff.
So I don't think we need the Makefile.inc for the i2c parts.
$39 for those boards is pretty attractive, do you have a link?
ron