PCI: host-generic: Avoid reporting incorrect 'missing reg property' error

PCI: host-generic: Avoid reporting incorrect 'missing reg property' error

When pci_host_common_ecam_create() calls of_address_to_resource(), it
assumes all errors are due to a missing "reg" property in the device tree
node, when they may be due to a malformed "reg" property.

This can manifest when running the qemu "virt" board with a 32-bit kernel
and `highmem=on` and leads to the very confusing error message:

  pci-host-generic 4010000000.pcie: host bridge /pcie@10000000 ranges:
  pci-host-generic 4010000000.pcie:       IO 0x003eff0000..0x003effffff -> 0x0000000000
  pci-host-generic 4010000000.pcie:      MEM 0x0010000000..0x003efeffff -> 0x0010000000
  pci-host-generic 4010000000.pcie:      MEM 0x8000000000..0xffffffffff -> 0x8000000000
  pci-host-generic 4010000000.pcie: missing "reg" property
  pci-host-generic 4010000000.pcie: probe with driver pci-host-generic failed with error -75

Make the error message more generic.

Link: https://www.qemu.org/docs/master/system/arm/virt.html
Signed-off-by: Jess <jess@jessie.cafe>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260120004444.191093-1-jess@jessie.cafe