Code:
-D 1,2can be used to enable both CPU and GPU (the Intel OpenCL Runtime for Core or Xeon processors need to be installed, in general), but note that it doesn't always increase speed by a lot because of 2 main reasons:
1. CPUs are often much slower than GPUs (much less cores etc)
2. the fact that the CPUs are now much more busy is often counter-productive, i.e. they can't provide the GPUs with enough work if they themself are busy cracking
This of course depends a lot on many factors, e.g. hash types and number of CPUs vs GPUs etc etc etc. It's something you could test and just not use if you see it's not significantly faser or doesn't help.