[POWERPC] Fix MAC address entries for 83xx, 85xx, and 86xx device trees

For the 83xx, 85xx, and 86xx device trees, add a "local-mac-address" property
to every Ethernet node that didn't have one.  Add a comment indicating that
the "address" and/or "mac-address" properties are deprecated in DTS files
and will be removed at a later time.  Change all MAC address properties to
have a zero MAC address value.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>