Revert commit b43eac6f (ACPICA: iASL: change processing of
external op namespace nodes for correctness; upstream ACPICA
commit aa866a9b4f24bbec9f158d10325b486d7d12d90f).

This was done in order to allow more relaxed usage of ASL external
declarations.
Signed-off-by: NErik Schmauss <erik.schmauss@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>