backports: handle new sriov_configure pointer in struct pci_driver

backports: handle new sriov_configure pointer in struct pci_driver

In kernel 3.8 struct pci_driver got a new function pointer sriov_configure.
Address this by putting ifdef around the code.

commit 1789382a72a537447d65ea4131d8bcc1ad85ce7b
Author: Donald Dutile <ddutile@redhat.com>
Date:   Mon Nov 5 15:20:36 2012 -0500

    PCI: SRIOV control and status via sysfs

git describe --contains 1789382a72a537447d65ea4131d8bcc1ad85ce7b
v3.8-rc1~128^2~6^2~4

Signed-off-by: Stefan Assmann <sassmann@kpanic.de>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>