I fail to see a relation between your code snippet and normal mapping. The HelloShader-example uses three textures. One base texture, a normal map and a height map. For proper normal (in this case parallax) mapping you either have to have this set of textures or you have to create the latter out of the former by using some tool that does this. I was using some command line tool for this, but i can't remember the name ATM. Armed with that, all you have to do is actually to replace the plane from the example with your own model.