The official Dehaze slider is only made available by Adobe in the Lightroom CC user interface.
However, the Dehaze functionality is also available in the Lightroom 6.1 code. It's just concealed (no slider in the LR6.1 UI).
You must upgrade from 6.0 to 6.1 to get the Dehaze functionality (minus the slider).
Then access Dehaze via a free plugin