Introduce new st,stm32mp25-rtc compatible. It is based on st,stm32mp1-rtc.

Difference is that stm32mp25 soc implements a triple protection on RTC
registers:
- Secure bit based protection
- Privileged context based protection
- Compartment ID filtering based protection
This driver will now check theses configurations before probing to avoid
exceptions and fake reads on register.

At this time, driver needs only to check two resources: INIT and ALARM_A.
Other resources are not used.

Resource isolation framework (RIF) is a comprehensive set of hardware
blocks designed to enforce and manage isolation of STM32 hardware
resources, like memory and peripherals.

Link: https://www.st.com/resource/en/reference_manual/rm0457-stm32mp25xx-advanced-armbased-3264bit-mpus-stmicroelectronics.pdf#page=4081Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20240708153434.416287-3-valentin.caron@foss.st.comSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>