ACPI: processor idle: Allow playing dead in C3 state

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 <[email protected]>
Signed-off-by: Richard Gong <[email protected]>
[ rjw: Fixed coding style ]
Signed-off-by: Rafael J. Wysocki <[email protected]>