http://bugzilla.kernel.org/show_bug.cgi?id=5165

Change polarity of test for PLVL2_UP flag.
Skip promotion/demotion code when not needed.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>