Mark zhimi.airp.mb3a as supported (#1468)

Author: rytilahti

miio/integrations/airpurifier/zhimi/airpurifier_miot.py

@@ -237,6 +237,7 @@
 _MAPPINGS = {
     "zhimi.airpurifier.ma4": _MAPPING,  # airpurifier 3
     "zhimi.airpurifier.mb3": _MAPPING,  # airpurifier 3h
+    "zhimi.airpurifier.mb3a": _MAPPING,  # airpurifier 3h
     "zhimi.airpurifier.va1": _MAPPING,  # airpurifier proh
     "zhimi.airpurifier.vb2": _MAPPING,  # airpurifier proh
     "zhimi.airpurifier.mb4": _MAPPING_MB4,  # airpurifier 3c