We do not currently have any functionality for building dexts with CMake, but it sounds like a very interesting project! If you can write a CMake module to do it (or, if necessary, modify CMake itself), I think we might be willing to add it to CMake.
FWIW, it is certainly possible to build things like kernels and drivers in CMake - ReactOS uses CMake, even for the kernel, and I myself have used it in attempting to write my own OS kernel.