Fix number of ADC attenuations for ESP32-C6

[jessebraham]

Quickly checked the other implementations as well, but I think they're all okay.

Closes #769

[JurajSadel]

Just an idea, what do you think about using constant in 'esp-hal-common/src/soc/esp32XX/mod.rs' instead of this config block?

[bjoernQ]

This fixes the original problem and should be good enough for now.
I like Juraj's idea - I guess that would be nicer.

The ideal solution IMHO would be to let the impl_adc_interface macro define the it. (And maybe move the chip specific instantiation of that macro to soc)

As said - this fixes the problem and the other suggestions might be something for a refactoring probably.

However: I cannot get ADC to work on C6 at all. It's always reads 0. Just wanted to confirm that ... maybe a me problem?

I'll approve this since it fixes the original problem. It's up to you if you want to explore the other approaches.

Would be good if someone else could verify if ADC works at all for you on C6 - if not we should create an issue and see what broke it

[bjoernQ]

LGTM - see my previous comment

[jessebraham]

The ideal solution IMHO would be to let the impl_adc_interface macro define the it. (And maybe move the chip specific instantiation of that macro to soc)

This would require adding additional macros to define the configuration and driver types, not sure it's really worth it for a constant used in 3 places in a single file, IMO.

However: I cannot get ADC to work on C6 at all. It's always reads 0. Just wanted to confirm that ... maybe a me problem?

Was not the case for me. Will do some more testing, though.