Not all linux version are the same. You look at it from another angle, but others have already looked via this very same angle as well. Unfortunately it is not the right angle. Android and Maemo differ very much. The Whatsapp program is closed source. If you want to build Whatsapp for a other architec the sources are needed. If the Whatsapp maker does not give the sources it is undouble. Whatsapp sources will most likely never become available.
You can get your hand on the source by going to work for Whatsapp as software engineer or so.