Describe the bug
A clear and concise description of what the bug is.
i had add new model 'zhimi.airpurifier.rma1' ，edit code in miio/integrations/airpurifier/zhimi/airpurifier_miot.py .
but have warning:
"Found an unsupported model 'zhimi.airpurifier.rma1' for class 'AirPurifierMiot'. If this is working for you, please open an issue at https://github.com/rytilahti/python-miio/ "
when call vac.status() can get device data <AirPurifierMiotStatus anion=None aqi=4 average_aqi=None xxxxxx >
Version information (please complete the following information):

• OS: [win10]
• python-miio: [0.5.11]

Device information:
If the issue is specific to a device [Use miiocli device --ip <ip address> --token <token> info]:

• Model: zhimi.airpurifier.rma1
• Hardware version: Xiaomi Smart Air Purifier 4 Lite
• Firmware version: v2.2.1

To Reproduce
Steps to reproduce the behavior:
1.

    vac = AirPurifierMiot(ip, token)
    print(vac.supported_models)
    info = vac.info()
    print("info")
    print(info)

[]
Found an unsupported model 'zhimi.airpurifier.rma1' for class 'AirPurifierMiot'. If this is working for you, please open an issue at https://github.com/rytilahti/python-miio/
info

Expected behavior
A clear and concise description of what you expected to happen.
run code with no warning
why AirPurifierMiot not have supported_models set ? but AirPurifier had set _supported_models = SUPPORTED_MODELS
Console output
If applicable, add console output to help explain your problem.
If the issue is about communication with a specific device, consider including the output using the --debug flag.