powercap: intel_rapl: Use topology interface in rapl_add_package()

It's not a good idea to access phys_proc_id and cpu_die_id directly.

Use topology_physical_package_id(cpu) and topology_die_id(cpu)
instead.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>