ARM: OMAP: Fix user space for omap2

Recent PTE global bit patch broke user space for omap2:

http://www.mail-archive.com/git-commits-head@vger.kernel.org/msg00119.html

The symptoms would be that commands would not return.

This fixes the problem, but there may be more to the issue than this.
Have also posted same patch to armlinux mailing list to verify it.