ARM: dts: stm32: add iwdg2 support for stm32mp157c-ed1

This patch activates independent watchdog support for
stm32mp157c board.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32mp157c-ed1.dts

@@ -57,6 +57,11 @@ &i2c4 {
 	status = "okay";
 };
 
+&iwdg2 {
+	timeout-sec = <32>;
+	status = "okay";
+};
+
 &rng1 {
 	status = "okay";
 };