ACPI: processor: Move processor_physically_present() to acpi_processor.c

Since _PDC method is deprecated and a preferred method of communicating
OSPM processor power management capabilities is _OSC, there is a need to
move function checking whether processor is present as this logic is not
_PDC specific.

Move processor_physically_present() to acpi_processor.c.

No intentional functional impact.

Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>