ARM: SAMSUNG: Move duplicate code for SPDIF ops

Move the duplicated code for SPDIF ops from S5PV210 and S5PC100.
So, the same can be used in EXYNOS4.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>