With the upstream migration to memory@BASE_ADDRESS naming scheme in the
device tree of some SoC families, we now have multiple overlapping memory
nodes in some of the barebox device trees. Rename the defunct overrides, so
they once again override the upstream nodes.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>