ACPICA: ACPI 6.0/iASL: Add support for the External AML opcode

ACPICA commit 882892feeafe8b8e5be10463133405cd4f1309d9

Support for both the compiler and disassembler.
Also, the interpreter will ignore this opcode if it
is ever encountered (should not happen).
David Box.

Link: https://github.com/acpica/acpica/commit/882892fe
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
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>

drivers/acpi/acpica/exoparg3.c

@@ -123,8 +123,10 @@ acpi_status acpi_ex_opcode_3A_0T_0R(struct acpi_walk_state *walk_state)
 		 * op is intended for use by disassemblers in order to properly
 		 * disassemble control method invocations. The opcode or group of
 		 * opcodes should be surrounded by an "if (0)" clause to ensure that
-		 * AML interpreters never see the opcode.
+		 * AML interpreters never see the opcode. Thus, something is
+		 * wrong if an external opcode ever gets here.
 		 */
+		ACPI_ERROR((AE_INFO, "Executed External Op"));
 		status = AE_OK;
 		goto cleanup;