Staging: add CSR wifi module

This consists of two modules, the driver, and a "helper" module that is
just a wrapper around common kernel functions.  The wrapper module will
be removed soon, but for now it's needed.

These files were based on the csr-linux-wifi-5.0.3-oss.tar.gz package
provided by CSR and Blue Giga, and is covered under the license
specified in the LICENSE.txt file (basically dual BSD and GPLv2).  The
files were flattened out of the deep directory mess they were originally
in, and a few EXPORT_SYMBOL_GPL() were added in order for everything to
link properly with the helper module setup.

Cc: Mikko Virkkilä <mikko.virkkila@bluegiga.com>
Cc: Lauri Hintsala <Lauri.Hintsala@bluegiga.com>
Cc: Riku Mettälä <riku.mettala@bluegiga.com>
Cc: Veli-Pekka Peltola <veli-pekka.peltola@bluegiga.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>