ACPI: cpufreq: Add highest perf change notification

Platform firmware sends notify 0x85 to inform the OS that the highest
performance of a CPU has changed.

This will be used by the AMD P-state driver to update the ranking of
preferred cores and set the priority of cores accordingly.

Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Meng Li <li.meng@amd.com>
Link: https://uefi.org/specs/ACPI/6.5/05_ACPI_Software_Programming_Model.html#processor-device-notification-values


[ rjw: New subject, changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>