ACPI: processor: Drop leftover acpi_processor_get_limit_info() declaration

Commit 22e7551e ("ACPI / processor: Remove acpi_processor_get_limit_info()"),
left it behind, so drop it.

Signed-off-by: Riwen Lu <luriwen@kylinos.cn>
Reviewed-by: Punit Agrawal <punit.agrawal@bytedance.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>