impl embedded_hal_async::i2c::I2c for I2cdev

[asasine]

Hello! I have a small sensor driver crate that only targets embedded-hal-async at the moment and wanted to check on the status of implementing such traits in linux-embedded-hal. Are there any obvious blockers for this? I may get a chance to try it soon and saw #109, which may be a good reference for a similar I2C implementation.

asasine/bmp390#1