PCI: Mark 64-bit resource as IORESOURCE_UNSET if we only support 32-bit

If we don't support 64-bit addresses, i.e., CONFIG_PHYS_ADDR_T_64BIT is not
set, we can't deal with BARs above 4GB.  In this case we already pretend
the BAR contained zero; this patch also sets IORESOURCE_UNSET so we can try
to reallocate it later.

I don't think this is exactly correct: what we care about here are *bus*
addresses, not CPU addresses, so the tests of sizeof(resource_size_t)
probably should be on sizeof(dma_addr_t) instead.  But this is what's been
in -next, so we'll fix that later.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/probe.c

@@ -252,6 +252,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 			/* Address above 32-bit boundary; disable the BAR */
 			pci_write_config_dword(dev, pos, 0);
 			pci_write_config_dword(dev, pos + 4, 0);
+			res->flags |= IORESOURCE_UNSET;
 			region.start = 0;
 			region.end = sz64;
 			bar_disabled = true;