x86, pci: detect end_bus_number according to acpi/e820 reserved, v2

x86, pci: detect end_bus_number according to acpi/e820 reserved, v2

Jack Howarth reported that 2.6.26-rc9-git9 doesn't boot on MacBookPro2.

the reason is a faulty BIOS update that reportes faulty resources.

Nevertheless it's possible for Linux to be more resolent about this
situation (and similar situations) and work around this bug, by
cross-checking the mmconf range against the e820 table and ACPI resources.

Change the mconf bus range from [0,0xff] to to [0, 0x3f]
to match range [0xf0000000, 0xf4000000) in e820 tables.

[ v2, yhlu.kernel@gmail.com:
  x86, pci: detect end_bus_number according to acpi/e820 reserved - fix ]

Reported-by: Jack Howarth <howarth@bromo.msbb.uc.edu>
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: jbarnes@virtuousgeek.org
Cc: Jack Howarth <howarth@bromo.msbb.uc.edu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>