Local variables used only in this file are made static.

[bhelgaas: also make pci_dev_attrs[] static (from Fengguang)]
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>