Remove unused cPickle from plotter.py
Remove unused cPickle from plotter.py

- cPickle is no longer directly available in python 3. If available, it
  automatically used when pickle is imported. cPickle is unused in the only
  place it is imported, so stop using it.

Signed-off-by: Daniel Wilson <c0a46a3457096bdbf302f01d2d37cf72d30c651c@intel.com>
Change-Id: I518cbc1e2e8e23d7f64430c3bcc06eac2cc054d3

cmcantalupo/geopm,geopm/geopm,cmcantalupo/geopm,cmcantalupo/geopm,cmcantalupo/geopm,geopm/geopm,cmcantalupo/geopm,geopm/geopm,geopm/geopm,geopm/geopm