I'm not sure adding this specific board makes sense.
- With 8 KB of flash, this board seems pretty limited and expensive.
- Adding more boards makes embedXcode more difficult to use and to maintain.
- How many users for this board?
You can try the procedure Add a Configuration File for a New Board described in the User Manual.
I recommend using the support page at http://embedxcode.weebly.com/onedesk.html