PCI: Make pcim_request_region() a public function

pcim_request_region() is the managed counterpart of pci_request_region().
It is currently only used internally for PCI.

It can be useful for a number of drivers and exporting it is a step towards
deprecating more complicated functions.

Make pcim_request_region() a public function.

Link: https://lore.kernel.org/r/20240729093625.17561-4-pstanner@redhat.com


Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>