PCI: Fix kernel-doc errors

Fix kernel-doc formatting errors, function names that don't match the doc,
and some missing parameter documentation.  These are reported by:

  make W=1 drivers/pci/

No functional change intended.

[bhelgaas: squashed into one patch since this only changes comments]
Link: https://lore.kernel.org/r/20210311001724.423356-1-kw@linux.com
Link: https://lore.kernel.org/r/20210311001724.423356-2-kw@linux.com
Link: https://lore.kernel.org/r/20210311001724.423356-3-kw@linux.com
Link: https://lore.kernel.org/r/20210311001724.423356-4-kw@linux.com
Link: https://lore.kernel.org/r/20210311001724.423356-5-kw@linux.com
Link: https://lore.kernel.org/r/20210311001724.423356-6-kw@linux.com
Link: https://lore.kernel.org/r/20210311001724.423356-7-kw@linux.com
Link: https://lore.kernel.org/r/20210311001724.423356-8-kw@linux.com


Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>