ACPI: processor: idle: Convert acpi_processor_setup_cpuidle_states() to void

ACPI: processor: idle: Convert acpi_processor_setup_cpuidle_states() to void

Since all callers of acpi_processor_setup_cpuidle_states() ignore its
return value and it simply passes the acpi_processor_setup_lpi_states()
return value to its callers, convert both of these functions to void.

No intentional functional impact.

Signed-off-by: Huisong Li <lihuisong@huawei.com>
[ rjw: Subject and changelog edits ]
Link: https://patch.msgid.link/20260120112258.1595164-2-lihuisong@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>