PCI: update location of PCI hotplug mailing lists

Just concentrate PCI traffic at linux-pci@vger rather than splitting it between
vger and a sf.net moderated (!) mailing list.

Acked-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Scott Murray <scottm@somanetworks.com>
Acked-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>