Dell support team contacted me and we were able to troubleshoot and solve it. So, here's the trick: BIOS version 1.5.0 is the key. I'm not sure which BIOS version my 7760 arrived with (I think it might have been 1.6.x), but I am sure that I downloaded and installed 1.7.0 (still got the file in my Downloads folder). During our troubleshooting the Dell rep pointed out that the latest version on their website is 1.5.0 and asked me to try it. I guess any newer versions got eventually pulled of without anyone really noticing, but downgrading to 1.5.0 really fixes it. First step: Turn off UEFI capsule firmware updates in your BIOS as a precaution. Windows OS sometimes upgrades the firmware right back, so this prevents it. I'm not sure if this would be the case as well, but since version 1.7.0 was displayed in the Device Manager I think that's what would happen. After downgrading the BIOS and rebooting the system NVIDIA Platform Controllers and Framework was displayed twice in the device manager, once in the error state and once working fine. I rebooted to safe mode, used DDU to uninstall the drivers, rebooted back to standard OS, quickly enabled airplane mode to prevent any automatic driver download and checked the Device Manager. NVIDIA Platform Controllers and Framework was still there twice (now both in error state), so I manually removed them from Device Manager, rebooted again, installed latest 511.79 drivers from Nvidia website and that was it. No more exclamation mark in the Device Manager, Platform Controllers and Framework is displayed once in the Device Manager without any error and after checking Nvidia Control Panel I can confirm that Dynamic Boost 2.0 is displayed as enabled. WhisperMode 2.0 is still with No next to it (meaning it's not working), but I'm not even sure if Quadro supports that, working Dynamic Boost 2.0 is the thing I was really after and that's now working. I haven't had the time yet to do any performance testing, but I think Dynamic Boost 2.0 will be noticable. Btw. there's a chance you can just downgrade the firmware, remove the device in error state from the Device Manager and call it a day. I did the whole DDU process just to be sure everything is clean.
I also found another problem in my laptop, in the device manager, one of the Nvidia devices does not start with error 31. and in the report of the Nvidia driver it is clear that 2 technologies do not work. (I highlighted them in the screenshot). Dinamic Boost 2.0 and WhisperMode 2.0 - does not work. [IMAGE][IMAGE][IMAGE] I found a description of a similar problem on the Nvidia forum, but there is no solution for my laptop.  [URL]  
new Dell Precision 7760, problem (conflict) with Nvidia platform controllers 
and framework