clk: amlogic: c3-peripherals: use helper for basic composite clocks

Use the composite clock helpers to define simple composite clocks of
the c3-peripherals clock controller.

This reduces the verbosity of the controller code on these very simple
parts, making maintenance simpler.

Reviewed-by: Chuan Liu <chuan.liu@amlogic.com>
Link: https://lore.kernel.org/r/20250825-meson-clk-cleanup-24-v2-12-0f402f01e117@baylibre.com
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

Author: jbrun3t