Sharmila, I understand that at this stage you may not be able to upgrade components to current versions. You are asking for help in extending the data model 3.16 had, and it is reasonable to ask the gpsd developers.
On the other hand, although Gary is trying, no one on this list is running a copy of 3.16. So we cannot really see the code you are modifying, and we would not want to run that on our test setups. Any changes you make to 3.16 would be of no use to our current users, anyway.
So any help is likely to be of the form: "try this, my memory says it might work, but ...".
I do not think anyone on this list is familiar with yocto, to make things worse.
The only advice I can give is to go back to Gary's email, and work with his suggestions. That may work. You will, of course, have to carry the support burden of porting the patch when yocto updates.
What I have done for OpenWRT updates, is to look at the gpsd build recipe (and build-specific patches), and apply them to a newer version (in this case 3.19). An example of the patches is at:
Apply these to a copy of 3.19 in your build tree.
If you can do this, we immediately can see what you are running, and may be able to help.