ACPI / processor: Remove acpi_processor_get_limit_info()

acpi_processor_get_limit_info() is only called in the __acpi_processor_start()
and what it does actually is just to check pr->flags.throttling and set limit.
The pr pointer has been checked in the __acpi_processor_start() before
acpi_processor_get_limit_info() being called. It doesn't make sense still to
keep it as a function. So move code to __acpi_processor_start() and remove
acpi_processor_get_limit_info().

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>