arm: plat-orion: remove addr-map code

Now that all Marvell EBU platforms have been converted to use the
mvebu-mbus driver, we can remove the common plat-orion/addr-map.c code
that isn't compiled anymore.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>