This post is about the exact problem I'm having, however the solution doesn't seem to be appropriate (I believe due to my kernel version). I'm using an AM3358.
The solution provided there was to make some modifications to board-am335x.c, which I assume is in the kernel source tree. That post was regarding kernel version 3.2, and I'm using linux-3.12.10-ti2013.12.01 and cannot find the file mentioned.
My guess is that this file was replaced with the device tree. In this case, how can I resolve this problem? Am I looking for that source file in the wrong place?