clk: samsung: add common clock framework helper functions for Samsung platforms

All Samsung platforms include different types of clock including
fixed-rate, mux, divider and gate clock types. There are typically
hundreds of such clocks on each of the Samsung platforms. To enable
Samsung platforms to register these clocks using the common clock
framework, a bunch of utility functions are introduced here which
simplify the clock registration process. The clocks are usually
statically instantiated and registered with common clock framework.

Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Tested-by: Tomasz Figa <t.figa@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>