[POWERPC] 85xx: Don't write reserved values to MAS1[TSIZE]

Some of the current tlbwe instructions early on in head_fsl_booke.S take
advantage of unarchitected behavior that allows the writing of reserved
values to the TSIZE field.  This patch corrects that, as well as an error
where an uninitialized (by linux) value was written into a MAS register and
used for a tlbwe.

Correct this for both arch/ppc and arch/powerpc.

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>