[POWERPC] Fix 8xx build breakage due to _tlbie changes

My changes to _tlbie to fix 4xx unfortunately broke 8xx build in a
couple of places.  This fixes it.

Spotted by Olof Johansson.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Vitaly Bordug <vitb@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>