*-pinctrl.dtsi: add pinctrl files for stm32mp2 soc

Add the pinctrl files for stm32mp2 soc series. These files are generated
from the open pin data repository, a subset of official release
STM32CubeMX 6.14.0, using the genpinctrl.py script.

Origin: ST Microelectronics
License: BSD-3-Clause
URL: https://github.com/STMicroelectronics/STM32_open_pin_data


Commit: 5e641448dc7df619ee46bb0c91796b7626005929
Purpose: *-pinctrl.dtsi for stm32mp2
Maintained-by: External

Signed-off-by: Youssef Zini <youssef.zini@savoirfairelinux.com>