drivers/clock_control: stm32 wb, wl: fix missing init of rcc prescalers
drivers/clock_control: stm32 wb, wl: fix missing init of rcc prescalers

This commit adds missing initialization of rcc prescalers for
stm32wb and stm32wl series when hse or hsi are selected as
system clock.

Signed-off-by: Thomas Stranger <289fb7da2789c69f49f06a4b4e006530cf91f1de@outlook.com>

zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr