Correct size comparison (pages vs. sections)

arch/arm/src/armv7-a/arm_addrenv.c

@@ -173,10 +173,13 @@ static int up_addrenv_create_region(FAR uintptr_t **list,
 
   /* Verify that we are configured with enough virtual address space to
    * support this memory region.
+   *
+   *   npages pages correspondes to (npages << MM_PGSHIFT) bytes
+   *   listlen sections corresponds to (listlen << 20) bytes
    */
 
   npages = MM_NPAGES(regionsize);
-  if (npages > listlen)
+  if (npages > (listlen << (20 - MM_PGSHIFT)))
     {
       bdbg("ERROR: npages=%u listlen=%u\n", npages, listlen);
       return -E2BIG;