PCI : Add selected_regions funcs

This patch adds the following changes into generic PCI code especially
for PCI legacy I/O port free drivers.

     - Added new pci_request_selected_regions() and
       pci_release_selected_regions() for PCI legacy I/O port free
       drivers in order to request/release only the selected regions.

     - Added helper routine pci_select_bars() which makes proper mask
       of BARs from the specified resource type. This would be very
       helpful for users of pci_enable_device_bars().

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>