ARM: orion5x: convert DT to use the mvebu-mbus driver

ARM: orion5x: convert DT to use the mvebu-mbus driver

This commit switches the Orion5x Device Tree files to use the DT
representation and probing for the mvebu-mbus driver. The changes are
mainly:

 * Re-organize the DT to follow the same organization as the one used
   on Armada 370/XP, which is needed for mvebu-mbus to work: a
   top-level soc { ... } node, which corresponds to the MBus bus, and
   a sub-node internal-regs { ... } for all peripherals whose register
   sit only in the "Internal Register Window". This change re-indents
   by one level the definition of all nodes in the Device Tree, which
   explains the large change.

 * Use custom functions orion5x_dt_init_early() and
   orion5x_dt_init_time() instead of orion5x_init_early() and
   orion5x_timer_init() as we now want the MBus driver to be probed
   from the Device Tree. We still use the old-style timer
   initialization, but that will be changed in a followup commit.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: https://lkml.kernel.org/r/1398202002-28530-14-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>