dt-bindings: arm: fsl: remove reduntant toradex,colibri-imx8x

'toradex,colibri-imx8x' is already present as a constant value for
'i.MX8QP Board with Toradex Colibri iMX8X Modules', so there is no need
to keep it twice as a enum value for 'i.MX8QXP based Boards'.
Signed-off-by: Hiago De Franco <hiago.franco@toradex.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/arm/fsl.yaml

@@ -1227,7 +1227,6 @@ properties:
           - enum:
               - einfochips,imx8qxp-ai_ml  # i.MX8QXP AI_ML Board
               - fsl,imx8qxp-mek           # i.MX8QXP MEK Board
-              - toradex,colibri-imx8x     # Colibri iMX8X Modules
           - const: fsl,imx8qxp
 
       - description: i.MX8DXL based Boards