x86: Add quirk to make Apple MacBookPro5,1 use reboot=pci

MacBookPro5,1 is not able to reboot unless reboot=pci is set.
This patch forces it through a DMI quirk specific to this
device.

Signed-off-by: Ozan Çağlayan <ozan@pardus.org.tr>
LKML-Reference: <1249403971-6543-1-git-send-email-ozan@pardus.org.tr>
Signed-off-by: Ingo Molnar <mingo@elte.hu>