clk: samsung: remove __clk_lookup() usage

clk: samsung: remove __clk_lookup() usage

__clk_lookup() interface is obsolete, so remove it from the Samsung clock
drivers. This has been achieved by getting rid of custom _get_rate()
helper and replacing it with clk_hw_get_rate().

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Link: https://lore.kernel.org/r/20211018125456.8292-2-m.szyprowski@samsung.com
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>