The CPU and GPU aren't really relevant in a DSLR. What does matter, though, is the efficiency of the sensor and the quality of the lenses. If I'm shooting a DSLR I'm also going to be editing the RAW data on a much, much more powerful device than a cell phone.
The point is that if DSLRs were to do onboard computational photography like OP wants them to it would require them to have more powerful CPUs and GPUs
