dt-bindings: display: sii902x: Add supply bindings

commit 4c1e0543 upstream.

The sii902x chip family requires IO and core voltages to reach the
correct voltage before chip initialization. Add binding for describing
the two supplies.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201020221501.260025-3-mr.nuke.me@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/display/bridge/sii902x.txt

@@ -8,6 +8,8 @@ Optional properties:
 	- interrupts: describe the interrupt line used to inform the host
 	  about hotplug events.
 	- reset-gpios: OF device-tree gpio specification for RST_N pin.
+	- iovcc-supply: I/O Supply Voltage (1.8V or 3.3V)
+	- cvcc12-supply: Digital Core Supply Voltage (1.2V)
 
 	HDMI audio properties:
 	- #sound-dai-cells: <0> or <1>. <0> if only i2s or spdif pin
@@ -54,6 +56,8 @@ Example:
 		compatible = "sil,sii9022";
 		reg = <0x39>;
 		reset-gpios = <&pioA 1 0>;
+		iovcc-supply = <&v3v3_hdmi>;
+		cvcc12-supply = <&v1v2_hdmi>;
 
 		#sound-dai-cells = <0>;
 		sil,i2s-data-lanes = < 0 1 2 >;