fix(stm32mp15-fdts): update clocks config for prtt1x board family

The clock driver and the DT bindings have changed for STM32MP1x boards
[1]. The prtt1x board family was missed when updating the other DT
files[2].

[1]: ae1e503763 feat(st-clock): update with new bindings
[2]: 4391e5edea feat(stm32mp1-fdts): new RCC DT bindings for STM32MP1

Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: Id461720fe7fcef125ba264ab96a855cdddf3843f
1 file changed