tools/power/x86/intel-speed-select: Introduce support for multi-punit

New platforms may have more than 1 punit in a Package/Die, thus it can
have multiple power domains in a Package/Die. Package id and die id is not
sufficient to refer to a specific Power domain.

Introduce support for multi-punit per package/die.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
[srinivas.pandruvada@linux.intel.com: changelog edits]
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>