powerpc/mm: use macro PGTABLE_EADDR_SIZE instead of digital
powerpc/mm: use macro PGTABLE_EADDR_SIZE instead of digital

In case of extending the eaddr in future, use this macro
PGTABLE_EADDR_SIZE to ease the maintenance of the code.

Signed-off-by: Liu Ping Fan <5e4a74fe21a1a42a20e1e6423070cafc7f9d333b@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <a7089bb6e7e92505d88aaff006cbdd60cc9120b6@kernel.crashing.org>

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