Patch originally written by Intel, cleaned up and made sane by 
Matthew Wilcox <willy@debian.org> and then tweaked a bit more by me.

From Matt's original email:
 - Add cfg_size to struct pci_dev.
 - Use it in sysfs and procfs.
 - Introduce pci_find_ext_capability() for finding extended capabilities.
 - Change the PCI_X_STATUS defines to match the spec (mea culpa there).
 - Add defines for the extended capabilities.