ARM: dts: stm32: add STMFX support on stm32mp157c-ev1

This patch adds support for STMicroelectronics Multi-Function eXpander
(STMFX) on stm32mp157c-ev1. It is connected on i2c2.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

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

@@ -99,6 +99,23 @@ &i2c2 {
 	i2c-scl-rising-time-ns = <185>;
 	i2c-scl-falling-time-ns = <20>;
 	status = "okay";
+
+	stmfx: stmfx@42 {
+		compatible = "st,stmfx-0300";
+		reg = <0x42>;
+		interrupts = <8 IRQ_TYPE_EDGE_RISING>;
+		interrupt-parent = <&gpioi>;
+		vdd-supply = <&v3v3>;
+
+		stmfx_pinctrl: stmfx-pin-controller {
+			compatible = "st,stmfx-0300-pinctrl";
+			gpio-controller;
+			#gpio-cells = <2>;
+			interrupt-controller;
+			#interrupt-cells = <2>;
+			gpio-ranges = <&stmfx_pinctrl 0 0 24>;
+		};
+	};
 };
 
 &i2c5 {