ACPICA: iASL: change processing of external op namespace nodes for correctness

ACPICA: iASL: change processing of external op namespace nodes for correctness

ACPICA commit aa866a9b4f24bbec9f158d10325b486d7d12d90f

The declaration External (ABCD.EFGH) creates two nodes in the namespace: ABCD
and EFGH where ABCD is marked as an implicit external node. ABCD is labeled as
implicit because there does not exist a specific External (ABCD) declaration.

Before this change, the declaration External (ABCD.EFGH) and
External (ABCD.EFGH.IJKL) creates the namespace nodes ABCD, EFGH, and IJKL
where ABCD and EFGH are labeled as implicit external nodes. This is incorrect.
The only implicit node should be ABCD because EFGH and IJKL are explicit nodes.
This change fixes the labeling procecess of external op namespace nodes so that
nodes are properly labeled as implicit external.

Due to this commit, the below ASL code results in a compilation error.

definition_block ("DSDT.aml", "DSDT", 0x02, "INTEL", "BDW    ", 0x0)
{
    External(\_SB.PCI0.GFX0, device_obj)
    External(\_SB.PCI0.GFX0.ALSI)

    Scope(\_SB)
    {
        Device(PCI0)
        {
            Device(GFX0)
            {
                Name(_ADR, 0x00020000)
            }
        }
    }
}

Link: https://github.com/acpica/acpica/commit/aa866a9b
Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>