ACPICA: Add macros to access pointer to next object in the descriptor list

Signed-off-by: Jung-uk Kim <jkim@FreeBSD.org>
Signed-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>
diff --git a/drivers/acpi/acpica/acmacros.h b/drivers/acpi/acpica/acmacros.h
index ed7943b..8b7ca40 100644
--- a/drivers/acpi/acpica/acmacros.h
+++ b/drivers/acpi/acpica/acmacros.h
@@ -322,8 +322,10 @@
  * where a pointer to an object of type union acpi_operand_object can also
  * appear. This macro is used to distinguish them.
  *
- * The "Descriptor" field is the first field in both structures.
+ * The "DescriptorType" field is the second field in both structures.
  */
+#define ACPI_GET_DESCRIPTOR_PTR(d)      (((union acpi_descriptor *)(void *)(d))->common.common_pointer)
+#define ACPI_SET_DESCRIPTOR_PTR(d, o)   (((union acpi_descriptor *)(void *)(d))->common.common_pointer = o)
 #define ACPI_GET_DESCRIPTOR_TYPE(d)     (((union acpi_descriptor *)(void *)(d))->common.descriptor_type)
 #define ACPI_SET_DESCRIPTOR_TYPE(d, t)  (((union acpi_descriptor *)(void *)(d))->common.descriptor_type = t)