ACPI: CPPC: Add definition for undefined FADT preferred PM profile value

ACPI: CPPC: Add definition for undefined FADT preferred PM profile value

In the event a new preferred PM profile value is introduced it's best for
code to be able to defensively guard against it so that the wrong settings
don't get applied on a new system that uses this profile but ancient
kernels.

Acked-by: Huang Rui <ray.huang@amd.com>
Suggested-by: Gautham Ranjal Shenoy <gautham.shenoy@amd.com>
Link: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#fixed-acpi-description-table-fadt
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>