pci-acpi: use local buffer for _OSC

Current pci-acpi implementation uses array in osc_data directly to
evaluate _OSC. It needs to save the old data and restore it if _OSC
evaluation fails. To make it more robust, we should use local array to
evaluate _OSC.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>