CPU frequence increasing on Raspberry Pi 
Since 1.3 I see a constant growth of CPU frequency of my Raspberry Pi 4

<img width="529" alt="Bildschirmfoto 2021-03-15 um 15 48 48" src="https://user-images.githubusercontent.com/55050117/111174070-6e360a00-85a7-11eb-87f2-4b568174ade8.png">

A restart of the Raspbian OS resets the frequency and it starts again


**Describe The Bug:**
Over time the CPU frequency of my Raspberry Pi 4 is constantly increasing.
A reboot fixes the issue but it starts again.
This was introduced when I switched to homebridge 1.3.x


**Expected behavior:**
Remain CPU frequency on a regular level

**Environment:**

* **Node.js Version**: 14.6.0
* **NPM Version**: 7.6.1
* **Homebridge Version**: 1.3.3
* **Operating System**: Raspbian 
* **Process Supervisor**: hb-service

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