powerpc/book3e: redefine pte_mkprivileged() and pte_mkuser()

Book3e defines both _PAGE_USER and _PAGE_PRIVILEGED, so the nohash
default pte_mkprivileged() and pte_mkuser() are not usable.

This patch redefines them for book3e.

In theorie, only pte_mkprivileged() needs to be redefined because
_PAGE_USER includes _PAGE_PRIVILEGED, but it is less confusing
to redefine both.

Fixes: a0da4bc1

 ("powerpc/mm: Allow platforms to redefine some helpers")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>