ARM: dts: omap4-droid4: add soundcard

Add sound support to Motorola Droid 4 using simple-soundcard
and CPCAP's audio codec. This does not yet correctly represent
the whole audio routing, since McBSP3 is also connected to
Bluetooth and MDM6600 modem (and probably also 4G modem).
These extra DAI links are not yet supported and have not been
tested.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>