PCI: Replace lkml.org, spinics, gmane with lore.kernel.org

The lkml.org, spinics.net, and gmane.org archives are not very reliable
and, in some cases, not even easily accessible.  Replace links to them with
links to lore.kernel.org, the archives hosted by kernel.org.

I found the gmane items via the Wayback Machine archive at
https://web.archive.org/

.

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