Interesting! There are significant numbers of self-identified "religious persons" throughout the world in different philosophy departments. You may find mostly Muslim philosophers in countries where the culture is Islamic, but that is not always true, as can be seen in the UK and USA. My own school includes a Hindu professor who shares a position with the religion and philosophy and you can find a guide to the many Christian philosophers working in the English-speaking world by looking at the Society of Christian Philosophers website. As for philosophy and spirituality, there are a few secular philosophers who have sought to promote a kind of spirituality without any religious affiliation or theistic framework (this was a project of Robert Solomon, for example). For a fascinating essay by one of the greatest living philosophers on the desire for some kind of spirituality, you should check out Thomas Nagel's essay "Secular Philosophy and the Religious Temperament." I think this is on his NYU website, but it is also available in a book by that title published with Oxford University Press.
Read another response by Charles Taliaferro
A recent while ago a person asked why their were so few religious persons in Philosophy departments these days. One philosopher responded that there were many opportunities for abstract thinking in the religion department of universities. Most religion departments are centered around particular religions such as Christianity while historically philosophers have often been spiritual but not affiliated with a religion. So I guess you could still ask why are so few philosophers spiritual in orientation and what educational department could they possibly turn to?