PCI: acpiphp_ibm: prepare for acpi_get_object_info() no longer returning status

acpi_get_object_info() is intended for early probe usage and as such should
not call any methods which may rely on OpRegions, but it used to also call
_STA to get the status, which on some systems does rely on OpRegions, this
behavior and the acpi_device_info.current_status member are being removed.

This commit prepares the acpiphp_ibm code for this by having it get the
status itself using acpi_bus_get_status_handle(). Note no error handling is
necessary on any errors acpi_bus_get_status_handle() leaves the value of
the passed in current_status at its 0 initialization value.

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>