clk: samsung: add support for CPU clocks

clk: samsung: add support for CPU clocks

Adds 'struct samsung_cpu_clock' and corresponding CPU clock registration
function to the samsung common clk driver. This allows samsung clock
drivers to register their CPU clocks with the samsung_cmu_register_one()
API.

Currently the exynos5433 apollo and atlas clks have their own custom
init functions to handle registering their CPU clocks. With this patch
we can drop their custom CLK_OF_DECLARE functions and directly call
samsung_cmu_register_one().

Signed-off-by: Will McVicker <willmcvicker@google.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211014195347.3635601-2-willmcvicker@google.com
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>