ARM: EXYNOS: Migrate clock support to common clock framework

ARM: EXYNOS: Migrate clock support to common clock framework

Remove Samsung specific clock support in Exynos4/5 and migrate to
use common clock framework.

Reviewed-by: Sylwester Nawrocki <[email protected]>
Tested-by: Sylwester Nawrocki <[email protected]>
Reviewed-by: Tomasz Figa <[email protected]>
Tested-by: Tomasz Figa <[email protected]>
Signed-off-by: Thomas Abraham <[email protected]>
Signed-off-by: Kukjin Kim <[email protected]>