PCI/PM: Print config space of devices before suspend

PCI/PM: Print config space of devices before suspend

When resuming from hibernation (S4, also known as "suspend to disk") on a
VM, we have seen invalid config space, e.g.,

  serial 0000:00:16.3: restoring config space at offset 0x14 (was 0x9104e000, writing 0xffffffff)

To help debug problems like this, log the config space being saved before
suspend, similar to the log in pci_restore_config_dword() when resuming.

Link: https://lore.kernel.org/r/20200113060724.19571-1-yu.c.chen@intel.com
[bhelgaas: commit log]
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Len Brown <lenb@kernel.org>