clk: samsung: Group CPU clock functions by chip

clk: samsung: Group CPU clock functions by chip

clk-cpu.c is going to get messy as new chips support is added.
Restructure the code by pulling related functions and definitions
together, grouping those by their relation to a particular chip or other
categories, to simplify the code navigation.

No functional change.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20240224202053.25313-7-semen.protsenko@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>