Luxmark does the same for me. Just reinstall the drivers from Nvidia to go back to "normal". The OpenCL patch just modifies one of the files in the Nvidia kexts.
I'm pretty sure the patch modified the OpenCL file which is in : /System/Library/Frameworks/OpenCL.framework/Versions/A/
The file was modified last time yesterday (at the exact time I patched it) when the other files/folders in there are all from Novembre 3, 2012, which is the day I installed my system.
So I am wondering if the other people here that are having this OpenCL trouble blocked at 2,1 had also patched this file before they install Nvidia drivers. Maybe it is interfering in some way ?
I would need the original OpenCL file to test it, but I don't know how to get.
EDIT : New FakeSMC/HWsensor installed, and same here, my GPU is at 30°C while idle.
My Build: Gigabyte GA-Z77X-UD5H | i7-3770K | MSI GTX 660 Twin Frozr |OS X 10.9