Update openocd config, add ChibiOS threads, rename for simplicity

[lukash]

Not sure the openocd config is in active use, the source paths didn't work for me (using STLink v3 minie):

• target/stm32f4x_stlink.cfg was not found
• openocd says interface/stlink-v2.cfg is depracated

I also added support for listing ChibiOS threads and renamed the file to a simpler name.

I finally figured out how to properly debug the package in gdb, planning on writing a short documentation for it, I'd like to reference this file.

[lukash]

@vedderb 🙏

Hoping this is trivial. As I said not sure the file is in active use, I can adjust the PR if needed.