memory: mvebu-devbus: add Orion5x support

memory: mvebu-devbus: add Orion5x support

This commit adds support for the Orion5x family of Marvell processors
into the mvebu-devbus driver. It differs from the already supported
Armada 370/XP by:

 * Having a single register (instead of two) for doing all the timing
   configuration.

 * Having a few less timing configuration parameters.

For this reason, a separate compatible string "marvell,orion-devbus"
is introduced.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Link: https://lkml.kernel.org/r/1398202002-28530-9-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>