media: dt-bindings: mt9p031: Add MT9P006 compatible string

Add compatible for MT9P006 sensor, which is older variant of MT9P031
and compatible with this driver.
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

Documentation/devicetree/bindings/media/i2c/aptina,mt9p031.yaml

@@ -17,6 +17,7 @@ description: |
 properties:
   compatible:
     enum:
+      - aptina,mt9p006
       - aptina,mt9p031
       - aptina,mt9p031m