samples: move mic/mpssd example code from Documentation

commit 6bee835dd54e279f3d3ae2eca92a9c394b4fd028 upstream.

Move mic/mpssd examples to samples and remove it from Documentation
Makefile. Create a new Makefile to build mic/mpssd. It can be built
from top level directory or from mic/mpssd directory:

Run make -C samples/mic/mpssd or cd samples/mic/mpssd; make

Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
[backported to 3.18-stable as this code is broken on newer versions of
 gcc and we don't want to break the build for a Documentation sample.
 - gregkh]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>