ACPI: processor: Rescan "dead" SMT siblings during initialization

Make acpi_processor_driver_init() call arch_cpu_rescan_dead_smt_siblings(),
via a new wrapper function called acpi_idle_rescan_dead_smt_siblings(),
after successfully initializing the driver, to allow the "dead" SMT
siblings to go into deep idle states, which is necessary for the
processor to be able to reach deep package C-states (like PC10) going
forward, so that power can be reduced sufficiently in suspend-to-idle,
among other things.

However, do it only if the ACPI idle driver is the current cpuidle
driver (otherwise it is assumed that another cpuidle driver will take
care of this) and avoid doing it on architectures other than x86.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/2005721.PYKUYFuaPT@rjwysocki.net