async I2C enhancement

[SoundsSerious]

I have been looking for an asynchronous implementation of I2C to interface with an MPU9250. I think this would be great to counter the extra overhead we'd get with the normal I2C polling on limited raspberry pi hardware.

Maybe this should be handled in a separate repo, but I think this library would plug in nicely. https://github.com/jabdoa2/smbus2_asyncio

I haven't tried imusensor yet but it seems like it would be straight forward to convert your smbus calls to async. This library could run the asynchronous task internally and raster or record the results, appearing synchronous to the user.

Unfortunately I'm currently in a bit of a rush to finish something, so I think I'm going to use threads to start but wanted to share this idea :)