Dimmer can not "Display As" switch - option not in HomeKit 
<!-- Provide a general summary in the Title above -->

Regular switches provide an option in HomeKit to treat as a switch or bulb. The dimmer only shows up as a bulb and does not have this option. I really want mine to show as a switch because I'm using it as a remove to control Hue lights using NodeRED and HomeBridge. Since this smart switch is controlling smart bulbs, I do not need to see the switch as a bulb.

### Versions
<!-- Please run commands and include versions below. -->
- **homebridge-tplink-smarthome**: `v6.1.0`
- **Node**:       `v14.15.1`
- **Homebridge**: `1.1.6`
- **MacOS**:         `10.15.7`

