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@xxxxxxxxxx>