drivers: i2c: stm32: exclude stm32f7 family for PM

The STM32F7 family does not yet support power management in Zephyr.

Besides, LL_I2C_EnableWakeUpFromStop and LL_I2C_DisableWakeUpFromStop

are not implemented in the H7 HAL/LL drivers

Signed-off-by: Fabrice DJIATSA <fabrice.djiatsa-ext@st.com>