ARM: S5P: Add platform helpers for camera GPIO configuration

Add functions for configuration of the parallel camera
bus pins on S5PV210 and Exynos4 SoC.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>