clk/samsung: add support for multuple clock providers

clk/samsung: add support for multuple clock providers

Samsung CCF helper functions do not provide support to
register multiple Clock Providers for a given SoC. Due to
this limitation SoC platforms are not able to use these
helpers for registering mulitple clock providers and are
forced to bypass this layer.

This layer is modified acordingly to enable the support.

Clockfile for exynos4, exynos5250, exynos5420, exynos5440
and S3c64xx are also modified as per changed helper functions.

Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
[t.figa: Backported to 3.10 kernel]
Signed-off-by: Tomasz Figa <t.figa@samsung.com>