The option you are trying to search may not be under the Intel® Graphics Control panel since the Dell Intelligent Display is a feature provided by the OEM only.
I recommend you to disconnect the AC adapter from the system, look for a dialog box for Dell Intelligent Display and click on it and set Dell Intelligent Display to off and see if the notebook will save your settings.
In the case that this step does not work, I recommend you contacting Dell so they can help you with the special feature in your computer.
Mine also doesn't show this option
I'm on a windows 8.1 running with bootcamp on a mac mini. Any ideas?
This feature may have been removed by the OEM in your system so I recommend you checking with Apple about this.