soc: arm: stm32wb has no PWR clock to enable
soc: arm: stm32wb has no PWR clock to enable

The stm32wb soc does not have any PWR clock
for its power IP block when initializing the module.

Signed-off-by: Francois Ramu <b83adc7f8a23ee911a37fcb61c4033581aae0b7a@st.com>

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