ARM: dts: stm32: Add watchdog support for STM32F429 SoC

Add watchdog into DT for stm32f429 family.
Signed-off-by: Yannick FERTRE <yannick.fertre@st.com>
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32f429.dtsi

@@ -65,7 +65,7 @@ clk-lse {
 			clock-frequency = <32768>;
 		};
 
-		clk-lsi {
+		clk_lsi: clk-lsi {
 			#clock-cells = <0>;
 			compatible = "fixed-clock";
 			clock-frequency = <32000>;
@@ -307,6 +307,13 @@ rtc: rtc@40002800 {
 			status = "disabled";
 		};
 
+		iwdg: watchdog@40003000 {
+			compatible = "st,stm32-iwdg";
+			reg = <0x40003000 0x400>;
+			clocks = <&clk_lsi>;
+			status = "disabled";
+		};
+
 		usart2: serial@40004400 {
 			compatible = "st,stm32-usart", "st,stm32-uart";
 			reg = <0x40004400 0x400>;