Some machines don't boot unless passed pci=nocrs.
(See https://bugzilla.redhat.com/show_bug.cgi?id=770308 for details of
  one report. Waiting on dmidecode output for others).

Currently there is a DMI whitelist, even though the default is on.

v2: drop the 1536 blacklist entry, superceded by the PNP/MMCONFIG changes from
    Bjorn
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>