x86/resctrl: Replace open coded cacheinfo searches

pseudo_lock_region_init() and rdtgroup_cbm_to_size() open code a search for
details of a particular cache level.

Replace with get_cpu_cacheinfo_level().

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240610003927.341707-5-tony.luck@intel.com