powerpc/8xx: Use PAGE size related consts
powerpc/8xx: Use PAGE size related consts

For PAGE size related operations, use PAGE size consts in order to be able to
use different page size in the futur.

Signed-off-by: Christophe Leroy <4e2d3d12816ace76f1cfa36c1816509bd24cf089@c-s.fr>
Signed-off-by: Scott Wood <b77916c2feab81a70245e7b5671f4f02730ebf64@freescale.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs