Add chuangmi.plug.212a01 support

[maybeloveu]

Name: Mi Smart Power Plug 2 (Wi-Fi and Bluetooth Gateway)
Model: chuangmi.plug.212a01

[syssi]

This issue needs to be fixed first: rytilahti/python-miio#844

[my7hcry]

when will this device supported

[xdxxp6qp]

???

[public-afant]

This issue needs to be fixed first: rytilahti/python-miio#844

Isn't this fixed yet?