hard_pwm: Add pin defs for STM32F070 and STM32F072

[willpuckett]

When experimenting with the new "pwm_pin" last week, I discovered that my toolhead board, an STM32F072, didn't have hardware pwm defined in Klipper.

This PR attempts to reconcile the above issue, and also includes pwm pin definitions for all processors in the STM32F0 family STM32F070.

Tests with my laser are greatly improved.

I am still tentative about ST's nomenclature. I also am not deeply aware of any other concerns I may need to take into consideration, i.e. ensuring that defined pins don't conflict with another portion of Klipper somehow.

In the rare circumstance in which a pin had multiple timers defined on different GPIO functions, the lower numbered function was used.

I utilized pin definitions from the following data sheets:

• STM32F031x4 STM32F031x6
• STM32F042x4 STM32F042x6
• STM32F070CB STM32F070RB STM32F070C6 STM32F070F6
• STM32F072x8 STM32F072xB

Common pins have been unioned as much as possible.

[willpuckett]

Build tests failed for STM32F031 and STM32F042, so removed them from the pull request.

[KevinOConnor]

Thanks. Commits need to have a signed-off-by line in order to be committed - see https://www.klipper3d.org/CONTRIBUTING.html .

Otherwise, the change looks fine to me.

Cheers, -Kevin

[willpuckett]

Thanks so much!

[KevinOConnor]

Thanks.

-Kevin