dBm should not be scaled with SI prefixes

<!-- Please only use this template for submitting feature requests --> **Why is this needed**: Measurements in dBm (desibel milliwatt) works best when not scaled. 0.9 dBm is more readable than 900 mdBm.  **What would you like to be added**: Scaling with SI prefixes should be turned off for dBm **Who is this feature for?** Anyone working with measurements given in dBm, for example fiber connections and wifi.