ARM: dts: stm32: add phy-dsi-supply property on stm32mp157c-ev1

The dsi physical layer is powered by the 1v8 power controller supply.
Signed-off-by: Yannick Fertré <yannick.fertre@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32mp157c-ev1.dts

@@ -101,6 +101,7 @@ dcmi_0: endpoint {
 &dsi {
 	#address-cells = <1>;
 	#size-cells = <0>;
+	phy-dsi-supply = <&reg18>;
 	status = "okay";
 
 	ports {