PCI: export SMBIOS provided firmware instance and label to sysfs

This patch exports SMBIOS provided firmware instance and label of
onboard PCI devices to sysfs.  New files are:
  /sys/bus/pci/devices/.../label which contains the firmware name for
the device in question, and
  /sys/bus/pci/devices/.../index which contains the firmware device type
instance for the given device.

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>