ACPI: Add documentation for exposing MRRM data

Initial implementation provides enumeration of the address ranges
NUMA node numbers, and BIOS assigned region IDs for each range.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://patch.msgid.link/20250505173819.419271-4-tony.luck@intel.com


Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>