Support DHT22 on expansion boards

[T3P3]

potentially along with DHT21

[T3P3]

Note BME280 is supported on the 3HC and it is likely a better choice than the DHT22, from our documentation:

The BME280 is recommended. DHT22 is supported, but is becoming harder to find. DHT21 is also supported, but is less accurate.

We are not planning on implementing this and encourage the use of more modern sensors. Time better spent on this FR: #1111