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.

arch/arm/mm/proc-v6.S

@@ -141,7 +141,7 @@ ENTRY(cpu_v6_set_pte)
 	orreq	r2, r2, #PTE_EXT_APX
 
 	tst	r1, #L_PTE_USER
-	orrne	r2, r2, #PTE_EXT_AP1
+	orrne	r2, r2, #PTE_EXT_AP1 | PTE_EXT_NG
 	bicne	r2, r2, #PTE_EXT_AP0
 	tstne	r1, #L_PTE_WRITE
 	tstne	r1, #L_PTE_DIRTY