dt-bindings: arm: stm32: Add Plymovent AQM board

Add support for the Plymovent AQM board based on the ST STM32MP151 SoC
to the STM32 devicetree bindings.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250305131425.1491769-3-o.rempel@pengutronix.de
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

Documentation/devicetree/bindings/arm/stm32/stm32.yaml

@@ -60,6 +60,7 @@ properties:
       - description: ST STM32MP151 based Boards
         items:
           - enum:
+              - ply,plyaqm   # Plymovent AQM board
               - prt,mecio1r0 # Protonic MECIO1r0
               - prt,mect1s   # Protonic MECT1S
               - prt,prtt1a   # Protonic PRTT1A