IEEE in ZHA configuration should be case-insensitive

[vvv2542]

In the device information IEEE is shown in upper case:

When copy-pasting, it is ignored in ZHA configuration and must be converted to lowercase for proper operation:

zha:
  device_config:
    A4:C1:38:64:XX:XX:XX:XX-1: # ignored
      type: switch
    a4:c1:38:64:XX:XX:XX:XX-1: # ok
      type: switch

I think that IEEE should be case-insensitive in configuration or output in lowercase if the configuration requires it.