There are a few choices:
1. You can either dismiss the message and prevent it from being displayed again but ticking the "Don't show this warning again" box.
2. This warning can be completely disabled in registry by setting the "WarningShow" value to 0 for the respective sensor under: HKEY_CURRENT_USER\SOFTWARE\HWiNFO64\Sensors
3. You can completely disable Embedded Controller (EC) support by disabling the "EC Support" option in general settings of HWiNFO. This equals to the LPC=0 option in the INI file. Note that by disabling this option, you will loose all EC sensor values.