This patch adds support for RAPL on Intel ValleyView based SoC
platforms, such as Baytrail.

Besides adding CPU ID, special energy unit encoding is handled
for ValleyView.
Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>