media: dt-bindings: media: adv7604: Fix slave map documentation

The reg-names property in the documentation is missing an '='. Add it.

Fixes: 9feb786876c7 ("media: dt-bindings: media: adv7604: Extend
bindings to allow specifying slave map addresses")

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/devicetree/bindings/media/i2c/adv7604.txt

@@ -66,7 +66,7 @@ Example:
 		 * other maps will retain their default addresses.
 		 */
 		reg = <0x4c>, <0x66>;
-		reg-names "main", "edid";
+		reg-names = "main", "edid";
 
 		reset-gpios = <&ioexp 0 GPIO_ACTIVE_LOW>;
 		hpd-gpios = <&ioexp 2 GPIO_ACTIVE_HIGH>;