There are four clock controllers in the A523 SoC. The existing binding already covers two of them that are critical for basic operation. The remaining ones are the MCU clock controller and CPU PLL clock controller. Add a description for the MCU CCU. This unit controls and provides clocks to the MCU (RISC-V) subsystem and peripherals meant to operate under low power conditions. Reviewed-by: Rob Herring (Arm) <robh@kernel.org> Link: https://patch.msgid.link/20250911174710.3149589-3-wens@kernel.org Signed-off-by: Chen-Yu Tsai <wens@csie.org>