Platform Runtime Mechanism (PRM) handlers can be invoked from either the AML
interpreter or directly by an OS driver. Implement the latter.

  [ bp: Massage commit message. ]
Signed-off-by: John Allen <john.allen@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20240730151731.15363-2-john.allen@amd.com