Add clockless driver for CH32 boards

[ahdinosaur]

Keen to find a non-SPI-hacking way to implement a clockless LED driver on the CH32 boards

• https://github.com/ch32-rs/ch32-hal

Not sure how to approach, help appreciated.

I bought boards from AliExpress to help with this:

• WeAct CH32V003F4U6
• WeAct CH32V203C8T6

Not a priority for me personally, but keen to do eventually.