[PATCH v2 27/30] patman: Switch over to asyncio

[Simon Glass]

Now that all the pieces are in place, switch over from using an executor
to using asyncio.

While we are here, import defaultdict to avoid needing to specify its
module.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

(no changes since v1)

 tools/patman/func_test.py |   4 +-
 tools/patman/patchwork.py |   8 +--
 tools/patman/status.py    | 137 ++++++++++++++++++++++++++++----------
 3 files changed, 105 insertions(+), 44 deletions(-)

Applied to sjg/master, thanks!