Add Support for TWatch 2020 Microphone

**Describe the problem you have/What new integration you would like**

The LilyGo Twach 2020 v3 has a PDM mic connected via i2c and a speaker connected via i2s.
**Please describe your use case for this integration and alternatives you've tried:**

I am trying to use the watch as a voice assistant but I cannot find if the mic is already supported or how to integrate it. It is unfortunately not connected via i2s but via i2c.

**Additional context**

Here is some specification about the device:
https://github.com/Xinyuan-LilyGO/TTGO_TWatch_Library/blob/master/docs/watch_2020_v3.md

Read the linked TWatch 2020 v3 specification first, focusing on the PDM microphone and its I2C connection. Then inspect the project’s existing device-audio support to determine whether this hardware can be integrated; done requires a defined microphone integration and documented voice-assistant use.

Written by the indexing model from the issue text.