`import numpy.distutils' gives people the following error.
ModuleNotFoundError: No module named 'multiprocessing'
Fix it by adding multiprocessing dependency.
(From OE-Core rev: 08198d658b3617ba5e124f82540eba5e41fdad6c)
Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>