ARM: dts: stm32: Add timer support for STM32F7

Add missing timer node to enable timer5 for STM32F7 SoCs family

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/arch/arm/dts/stm32f746.dtsi b/arch/arm/dts/stm32f746.dtsi
index 46d148e..8c6fa13 100644
--- a/arch/arm/dts/stm32f746.dtsi
+++ b/arch/arm/dts/stm32f746.dtsi
@@ -323,6 +323,13 @@
 			pinctrl-names = "default", "opendrain";
 			max-frequency = <48000000>;
 		};
+
+		timer5: timer@40000c00 {
+			compatible = "st,stm32-timer";
+			reg = <0x40000c00 0x400>;
+			interrupts = <50>;
+			clocks = <&rcc 0 STM32F7_APB1_CLOCK(TIM5)>;
+		};
 	};
 };