nios2: basic build, non-functional

Basic build framework for Nios2. Everything is stubbed out,
we just want to have a build going so that we can start to
parallelize implementation tasks.

This patch is not intended to be functional, but should be
able to produce a binary for all the nanokernel-based
sanity checks.

Change-Id: I12dd8ca4a2273f7662bee46175822c9bbd99202a
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>