ACPICA: Fix to allow region arguments to reference other scopes

Allow referenced objects to be in a different scope.

http://www.acpica.org/bugzilla/show_bug.cgi?id=937
http://marc.info/?l=linux-acpi&m=131636632718222&w=2



ACPI Error: [RAMB] Namespace lookup failure, AE_NOT_FOUND (20110112/psargs-359)
ACPI Exception: AE_NOT_FOUND, Could not execute arguments for [RAMW] (Region) (20110112/nsinit-349)

    Scope (_SB)
    {
        Name (RAMB, 0xDF5A1018)
        OperationRegion (\RAMW, SystemMemory, RAMB, 0x00010000)
    }

For above ASL code, we need to save scope node(\_SB) to lookup
the argument node(\_SB.RAMB).

Reported-by: Jim Green <student.northwestern@gmail.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>