ADC: Accept configuration struct as argument to method Configure

[ardnew]

I think it makes sense to change the API of ADC.Configure (for all chips) to the API you're using here. The reason is that an ADC actually has a number of important configurations for different tradeoffs:

• Reference voltage (often VCC, but sometimes 1.1V or some other value).
• Accuracy vs time. I know that the nrf chips have this tradeoff (where more accurate sampling takes a lot longer but is necessary if there is a big resistor on the input) and I would guess other ADCs have something similar.

Of course, it's not necessary to implement them all right away but with this I think it makes sense to add an ADCConfig to the peripheral.

Originally posted by @aykevl in #1458 (comment)

[deadprogram]

This has been released with v0.17.0 so now closing. Thanks!