When we start using a new pagetable (for a new process)
the last part is to ensure the pagetable itself can be
accessed by VM. This is done in pt_bind by updating
the "pagetable of pagetables" and we want this mapping
to match other mappings to the l1 pagetable.
Change-Id: I7b506fd75553917fdc1abd25b55e4b2f25ccbf8d