tools/power/x86/intel-speed-select: Add support for core-power discovery

It is possible that BIOS may not enable core-power feature. In this case
this additional interface will allow to enable from this utility. Also
the information dump, includes the current status of core-power.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>