PCI: generic: Claim bus resources on PCI_PROBE_ONLY set-ups

We claim PCI BAR and bridge window resources in pci_bus_assign_resources(),
but when PCI_PROBE_ONLY is set, we treat those resources as immutable and
don't call pci_bus_assign_resources(), so the resources aren't put in the
resource tree.

When the resources aren't in the tree, they don't show up in /proc/iomem,
we can't detect conflicts, and we need special cases elsewhere for
PCI_PROBE_ONLY or resources without a parent pointer.

Claim all PCI BAR and window resources in the PCI_PROBE_ONLY case.

If a PCI_PROBE_ONLY platform assigns conflicting resources, Linux can't fix
the conflicts.  Previously we didn't notice the conflicts, but now we will,
which may expose new failures.

[bhelgaas: changelog, summarize comment]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: David Daney <david.daney@cavium.com>