ACPI: processor idle: Allow playing dead in C3 state

When some cores are disabled on AMD platforms, the system will no longer
be able to enter suspend-to-idle s0ix.

Update to allow playing dead in C3 state so that the CPUs can enter the
deepest state on AMD platforms.

BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1708


Suggested-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Richard Gong <richard.gong@amd.com>
[ rjw: Fixed coding style ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>