PCI: Merge pci_dev_resource_x and pci_dev_resource

pci_dev_resource_x is a superset of pci_dev_resource and they're just
temp structs used during resource reallocation.

pci_dev_resource usage is quite limted.

So just use pci_dev_resource_x, and rename it as new pci_dev_resource.

-v2: According to Linus, Separate free_list change to another patch

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>