They should automatically be carried over through your MATLAB preferences.
If they are not for some reason, you can using slrtTargets = SimulinkRealTime.getTargetSettings('-all'); to store your target settings in a MATLAB variable. You can then save this to a MAT file.
From there, you can import the MAT file into the new version of MATLAB and use SimulinkRealTime.addTarget to add the different targets.
Again, I don't suspect you'll need to do that. They should come over through your MATLAB preferences (assuming your new MATLAB version is installed on the same computer your old one was).