No problem at all. If you view this article:

http://www.backyardgardening.net/art...ck-raised-bed/

It is exactly what I did.

Because you are raising the soil near the foundation, you're actually improving the grade. The bed will drain really well, so don't plant something that has high water needs in it, and if you want, you could smear waterproofer on the brick first, but I didn't.