clk: exynos5420: register clocks using common clock framework

The EXYNOS5420 clocks are statically listed and registered using
the Samsung specific common clock helper functions.

Signed-off-by: Chander Kashyap <chander.kashyap@linaro.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Cc: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>