ARM: orion5x: convert RD-88F5182 to Device Tree

ARM: orion5x: convert RD-88F5182 to Device Tree

This commit converts the RD-88F5182 platform to the Device Tree. All
devices except the PCI are converted to the Device Tree.

It is worth noting that:

 * The PCI description for the DT case is kept in board-rd88f5182.c.

 * The existing non-DT support in rd88f5182-setup.c is kept as is, in
   order to allow testing of a given platform in both DT and non-DT
   cases. It will ultimately be removed, once we no longer care about
   non-DT support for Orion5x.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: https://lkml.kernel.org/r/1398202002-28530-35-git-send-email-thomas.petazzoni@free-electrons.com
Cc: Ronen Shitrit <rshitrit@marvell.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>