ACPICA commit 81a89968f83bfc3b1d0f0f80f2da08ea69646053

Adds a lengthy comment to acpi_get_object_info explaining the removal
of _SUB and why no complex methods can be added ever to this
interface.

Link: https://github.com/acpica/acpica/commit/81a89968Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>