ARM: dts: stm32: Add power-supply for DSI panel on stm32f469-disco

Add a fixed regulator and use it as power supply for DSI panel.

Fixes: 18c88662 ("ARM: dts: stm32: Add display support on stm32f469-disco")
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32f469-disco.dts

@@ -76,6 +76,13 @@ mmc_vcard: mmc_vcard {
 		regulator-max-microvolt = <3300000>;
 	};
 
+	vdd_dsi: vdd-dsi {
+		compatible = "regulator-fixed";
+		regulator-name = "vdd_dsi";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+	};
+
 	soc {
 		dma-ranges = <0xc0000000 0x0 0x10000000>;
 	};
@@ -155,6 +162,7 @@ panel-dsi@0 {
 		compatible = "orisetech,otm8009a";
 		reg = <0>; /* dsi virtual channel (0..3) */
 		reset-gpios = <&gpioh 7 GPIO_ACTIVE_LOW>;
+		power-supply = <&vdd_dsi>;
 		status = "okay";
 
 		port {