ACPICA: Disassembler: add external op to namespace on first pass

ACPICA commit 117be4819588df3b7146f6f01723639b1d61e775

By doing so, external control method resolutions can be resolved like
normal control methods. This eliminates the need to reparse the aml
all over again for external control methods that were encoded within
the aml with the 0x15 bytecode.

Link: https://github.com/acpica/acpica/commit/117be481


Signed-off-by: Erik Schmauss <erik.schmauss@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>