PCI/ACPI: rename pci_osc_control_set()

- Rename pci_osc_control_set() to acpi_pci_osc_control_set() according
  to the other API names in drivers/acpi/pci_root.c.

- Move _OSC related definitions to include/linux/acpi.h because _OSC
  related API is implemented in drivers/acpi/pci_root.c now.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Andrew Patterson <andrew.patterson@hp.com>
Tested-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>