MAINTAINERS: Add ADV7180 bindings documentation

Add the YAML dt-bindings document for ADV7180.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Rob Herring <robh@kernel.org>

MAINTAINERS

@@ -1073,6 +1073,7 @@ L:	linux-media@vger.kernel.org
 S:	Supported
 W:	http://ez.analog.com/community/linux-device-drivers
 F:	drivers/media/i2c/adv7180.c
+F:	Documentation/devicetree/bindings/media/i2c/adv7180.yaml
 
 ANALOG DEVICES INC ADV748X DRIVER
 M:	Kieran Bingham <kieran.bingham@ideasonboard.com>