YB: #6254
This module uses os but relies on other modules to import it. Adding 'import os' in order to be self-sustained.
(From OE-Core rev: 26e4d5212ec5b2bcfdb0f42bbed31f468a17aca4)
Signed-off-by: Corneliu Stoicescu <corneliux.stoicescu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>