[Balloon] Fixing the depmod problem

Until we have a modules.dep with absolute paths, the modprobe won't work.
Until that happens I guess I really don't have an easy way to transfer test
scripts etc onto the board.

I thought it would be easy to use sed to massage the modules.dep but for
some reason the places I added them in the Makefile to didn't get called.
Clearly I don't understand the make dependencies properly.

Any hints on where to inject such sedness welcome.

Thanks.

Charles