dt-bindings: adi,adv7511.txt: document cec clock

Document the cec clock binding.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20171007104658.14528-2-hverkuil@xs4all.nl

Documentation/devicetree/bindings/display/bridge/adi,adv7511.txt

@@ -68,6 +68,8 @@ Optional properties:
 - adi,disable-timing-generator: Only for ADV7533. Disables the internal timing
   generator. The chip will rely on the sync signals in the DSI data lanes,
   rather than generate its own timings for HDMI output.
+- clocks: from common clock binding: reference to the CEC clock.
+- clock-names: from common clock binding: must be "cec".
 
 Required nodes:
 
@@ -89,6 +91,8 @@ Example
 		reg = <39>;
 		interrupt-parent = <&gpio3>;
 		interrupts = <29 IRQ_TYPE_EDGE_FALLING>;
+		clocks = <&cec_clock>;
+		clock-names = "cec";
 
 		adi,input-depth = <8>;
 		adi,input-colorspace = "rgb";