pci-acpi: add flag to indicate query had been done

Current pci-acpi implementation checks osc_data->support_stat to see
if control bits had been already queried. It is not good from the
viewpoint of easy understanding. So this patch adds new 'is_queried'
flag to indicate query had been done.

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>