dt-bindings: arm: fsl: Add carriers for toradex,colibri-imx6dl

Add bindings for Aster, Iris and Iris V2 carrier boards our
Colibri iMX6S/DL may be mated with.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/arm/fsl.yaml

@@ -487,7 +487,10 @@ properties:
       - description: i.MX6DL Boards with Toradex Colibri iMX6DL/S Modules
         items:
           - enum:
+              - toradex,colibri_imx6dl-aster        # Colibri iMX6DL/S Module on Aster Board
               - toradex,colibri_imx6dl-eval-v3      # Colibri iMX6DL/S Module on Colibri Evaluation Board V3
+              - toradex,colibri_imx6dl-iris         # Colibri iMX6DL/S Module on Iris Board
+              - toradex,colibri_imx6dl-iris-v2      # Colibri iMX6DL/S Module on Iris Board V2
           - const: toradex,colibri_imx6dl           # Colibri iMX6DL/S Module
           - const: fsl,imx6dl