ACPI: PM: s2idle: Add support for multiple func mask

Required for follow-up patch adding new UUID needing new function
mask.

Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma@amd.com>
Tested-by: Julian Sikorski <belegdol@gmail.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>