Holographic renormalization for non-conformal branes, i.e. non-AdS/non-CFT systems, was systematically developed in [this paper][1] by Kanitscheider, Skenderis and Taylor. They even work it out for the example of the Witten model, which is the background of the Sakai-Sugimoto model. 

The key principle that permits one to extend the formalism of holographic renormalization to non-conformal systems is the so-called *generalized conformal structure.* This can be understood as follows: if you extend conformal transformations in such a way that the coupling constant of the boundary Yang-Mills theory transforms like an operator of appropriate dimension, the theory possesses a (generalized) conformal invariance. This allows for an asymptotic Fefferman-Graham expansion and the construction of a renormalized action from which you can derive (renormalized) n-point functions.     


  [1]: http://arxiv.org/abs/arXiv:0807.3324