ASoC: Remove to support sound for S5P6442

According to removing ARCH_S5P6442, we don't need to support
sound for S5P6442.

Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>