ASoC: exynos: organize the asoc audio into a menu

It is simple sound card time, we could assign different codec
to a interface without making a specific driver for it. The SPDIF
and I2S interface for Samsung would be possible used by
simple-sound-card, but not sure about the PCM.

Those S3C time entries are left alone as I don't think any new board
would need them.

Signed-off-by: Randy Li <ayaka@soulik.info>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>