ARM: dts: Add sound-card name for Snow/Peach-Pit/Peach-Pi

Add sound-card name property to Snow/Peach-Pit/Peach-Pi boards.

Signed-off-by: Tushar Behera <tushar.b@samsung.com>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>