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 <[email protected]>
Suggested-by: Gautham Ranjal Shenoy <[email protected]>
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 <[email protected]>
Reviewed-by: Perry Yuan <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

Author: superm1

include/acpi/actbl.h

@@ -307,7 +307,8 @@ enum acpi_preferred_pm_profiles {
 	PM_SOHO_SERVER = 5,
 	PM_APPLIANCE_PC = 6,
 	PM_PERFORMANCE_SERVER = 7,
-	PM_TABLET = 8
+	PM_TABLET = 8,
+	NR_PM_PROFILES = 9
 };
 
 /* Values for sleep_status and sleep_control registers (V5+ FADT) */