dt-bindings: pinctrl: stm32: add new compatible for STM32MP135 SoC

New compatible to manage ball out and pin muxing of STM32MP135 SoC.
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de
Link: https://lore.kernel.org/r/20210723132810.25728-2-alexandre.torgue@foss.st.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.yaml

@@ -24,6 +24,7 @@ properties:
       - st,stm32f746-pinctrl
       - st,stm32f769-pinctrl
       - st,stm32h743-pinctrl
+      - st,stm32mp135-pinctrl
       - st,stm32mp157-pinctrl
       - st,stm32mp157-z-pinctrl