ARM: mvebu: use simple-card DT binding for audio on Armada 370 DB

ARM: mvebu: use simple-card DT binding for audio on Armada 370 DB

This commit modifies the Armada 370 and Armada 370 DB Device Tree
descriptions to use the simple-card DT binding to describe the audio
complex of the Armada 370 DB instead of a custom audio machine driver.

To do so, it:

 - Adds the sound-dai-cells properties to the CS42L51 node, the audio
   controller node and the SPDIF in/out nodes.

 - Completely changes the description of the sound complex to use the
   "simple-audio-card" DT binding instead of the
   "marvell,a370db-audio" DT binding.

 - Fixes the indentation to properly use tabs instead of spaces.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1414512524-24466-6-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>