clk: samsung: Constify clock init data with clock arrays

samsung_cmu_register_one() can accept pointer to const initialization
data: struct samsung_cmu_info. The members of the latter can also be
pointers to const data.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>