drivers: i2c: stm32: exclude stm32f7 family for PM in RTIO driver

Exclude STM32F7 SoC series from PM support since that SoC doees not
yet manage power management in Zephyr and HAL API functions
LL_I2C_EnableWakeUpFromStop() and LL_I2C_DisableWakeUpFromStop()
are not implemented in the H7 HAL/LL drivers.

This change ports into the STM32 RTIO driver the change made in the
non-RTIO driver through commit 1804eb7b ("drivers: i2c: stm32:
exclude stm32f7 family for PM").

Back ported from commit 5ff3dbee ("drivers: i2c: stm32: exclude
stm32f7 family for PM in RTIO driver").

Signed-off-by: Etienne Carriere <etienne.carriere@st.com>