fix armv7 bug on linux

Hi, I was facing this problem on my linux box:
https://github.com/facebook/atosl/issues/4

So I fixed using the following code (all credit to @hawflakes) and now is working:
https://gist.github.com/hawflakes/9677613

- I had to update the config.mk file to avoid warnings to be treat as errors


Best regards
Christian