PCI: enable pci=bfsort by default on future Dell systems

This patch enables pci=bfsort by default on future Dell systems.
It reads SMBIOS type 0xB1 vendor specific record and sets pci=bfsort
accordingly.

Offset  Name    Length  Value   Description

04      Flags0  Word    Varies  Bits 9-10
                                - 10:9 = 00  Unknown
                                - 10:9 = 01  Breadth First
                                - 10:9 = 10  Depth First
                                - 10:9 = 11  Reserved

1. Any time pci=bfsort has to be enabled on a system, we need to add the
   model number of the system to the white list. With this patch, that
   is not required.

2. Typically, model number has to be added to the white list when the
   system is under development. With this change, that is not required.

Signed-off-by: Jordan Hargrave <jordan_hargrave@dell.com>
Signed-off-by: Narendra K <narendra_k@dell.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>