ARM: dts: Add devicetree for Eckelmann ci4x10

This is one of two boards that make use of the recently introduced SIOX
bus. Apart from the devices described in the dts it features a display
with touch that I didn't include here because it needs some non-mainline
change to operate correctly.

Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>