modules: Delete switches USE_STM32_HAL_RCC and USE_STM32_HAL_RCC_EX

With STM32Cube updates
https://github.com/zephyrproject-rtos/hal_stm32/pull/75


'..._hal_rcc.c' and '..._hal_rcc_ex.c' are now systematically
compiled, due to more and more dependencies from HAL IP on rcc.
So USE_STM32_HAL_RCC and USE_STM32_HAL_RCC_EX becomes useless.

Signed-off-by: Alexandre Bourdiol <alexandre.bourdiol@st.com>