BUG: Fix for #37454: allow reversed axis when plotting with TimedeltaIndex
- [x] closes #37454
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

@jreback, looks like everything is working except some unrelated failures with FutureWarning. @jreback, I think this is good to go thanks @theavey very nice