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>

drivers/acpi/acpica/acobject.h

@@ -358,6 +358,7 @@ typedef enum {
  */
 struct acpi_object_extra {
 	ACPI_OBJECT_COMMON_HEADER struct acpi_namespace_node *method_REG;	/* _REG method for this region (if any) */
+	struct acpi_namespace_node *scope_node;
 	void *region_context;	/* Region-specific data */
 	u8 *aml_start;
 	u32 aml_length;