ARM: dts: da850-lcdk: Audio support via simple-card

The LCDK embeds a TLV320AIC3106 connected to the SoC McASP for analog
audio. The power supply of the codec comes from the main PMIC
(TPS650250) DCDCs which are always on per HW design and not
controllable by SW, so SW wise the codec driver will rely on the 'dummy'
regulator.
Quality is good with arecord -pipe- aplay on Line In/Line Out.

Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Karl Beldan <kbeldan@baylibre.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>