clk: samsung: exynos3250: Move platform driver and of_device_id to init section

The platform_driver and of_device_id structs can be moved to init
section because they are referenced only from subsys_initcall-level
function.

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