Code uses pkg_id and die_id to refer to a specific power domain.

The pkg/die information is already settled at start time. Adding package
id and die id information into struct isst_id so that code does not need
to retrieve them at runtime.

More code cleanups can be done with the package/die info available.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>