hw/misc/stm32l4x5_rcc: Propagate period when enabling a clock

hw/misc/stm32l4x5_rcc: Propagate period when enabling a clock

The "clock_set_mul_div" function doesn't propagate the clock period
to the children if it is changed (e.g. by enabling/disabling a clock
multiplexer).
This was overlooked during the implementation due to late changes.

This commit propagates the change if the multiplier or divider changes.

Fixes: ec7d83acbd ("hw/misc/stm32l4x5_rcc: Add an internal clock multiplexer object")
Signed-off-by: Arnaud Minier <arnaud.minier@telecom-paris.fr>
Signed-off-by: Inès Varhol <ines.varhol@telecom-paris.fr>
Message-ID: <20240317103918.44375-2-arnaud.minier@telecom-paris.fr>
[PMD: Check clock_set_mul_div() return value]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20240325152827.73817-4-philmd@linaro.org>