x86: SB450: deprioritize DMI quirks

This PCI ID based quick should be a full solution for the IRQ0 override
related slowdown problem on SB450 based systems:

  33fb0e4e

: x86: SB450: skip IRQ0 override if it is not routed to INT2 of IOAPIC

Emit a warning in those cases where the DMI quirk triggers but
the PCI ID based quirk didnt.

If this warning does not trigger then we can phase out the DMI quirks.

Signed-off-by: Ingo Molnar <mingo@elte.hu>