ACPICA: Add __init for ACPICA initializers/finalizers.

This patch adds __init to the ACPICA documented initializers:
  acpi_initialize_tables()
  acpi_initialize_subsystem()
  acpi_load_tables()
  acpi_enable_subsystem()
  acpi_initialize_objects()
and to acpi_reallocate_root_table(), acpi_find_root_pointer() which
are also meant to be called only during initialization.

This patch adds __init to the ACPICA documented finalizer:
  acpi_terminate()
as this finalizer is only called in __init function now.

This change helps to reduce source code differences between
ACPICA upstream and Linux.

[rjw: Changelog]
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/utxfinit.c

@@ -65,7 +65,7 @@ ACPI_MODULE_NAME("utxfinit")
  *              called, so any early initialization belongs here.
  *
  ******************************************************************************/
-acpi_status acpi_initialize_subsystem(void)
+acpi_status __init acpi_initialize_subsystem(void)
 {
 	acpi_status status;
 
@@ -140,7 +140,7 @@ ACPI_EXPORT_SYMBOL_INIT(acpi_initialize_subsystem)
  *              Puts system into ACPI mode if it isn't already.
  *
  ******************************************************************************/
-acpi_status acpi_enable_subsystem(u32 flags)
+acpi_status __init acpi_enable_subsystem(u32 flags)
 {
 	acpi_status status = AE_OK;
 
@@ -245,7 +245,7 @@ ACPI_EXPORT_SYMBOL_INIT(acpi_enable_subsystem)
  *              objects and executing AML code for Regions, buffers, etc.
  *
  ******************************************************************************/
-acpi_status acpi_initialize_objects(u32 flags)
+acpi_status __init acpi_initialize_objects(u32 flags)
 {
 	acpi_status status = AE_OK;