PCI: handle 64-bit resources better on 32-bit machines

If the kernel is configured to support 64-bit resources on a 32-bit
machine, we can support 64-bit BARs properly.  Just change the condition
to check sizeof(resource_size_t) instead of BITS_PER_LONG.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>