[Buildroot] Adding a new architecture

[Marc Gauthier]

Hi,

We've ported buildroot to the Xtensa architecture.
(It currently lives on linux-xtensa.org .)
At some point in the near future, we'll be getting ready to submit
the port to the buildroot patch tracker.

Shall we simply submit the whole thing in one big patch?

We'll omit unrelated fixes that we can post later.  However, some
of the changes touch common code.  Do we post some of these first?

Thanks,
-Marc