ARM: dts: stm32: add low power timer on STM32F746

Add device tree node for the low power timer on the STM32F746.

Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
Link: https://lore.kernel.org/r/20250404143514.860126-1-ben.wolsieffer@hefring.com
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

arch/arm/boot/dts/st/stm32f746.dtsi

@@ -43,6 +43,7 @@
 #include "../armv7-m.dtsi"
 #include <dt-bindings/clock/stm32fx-clock.h>
 #include <dt-bindings/mfd/stm32f7-rcc.h>
+#include <dt-bindings/interrupt-controller/irq.h>
 
 / {
 	#address-cells = <1>;
@@ -245,6 +246,39 @@
 			};
 		};
 
+		lptimer1: timer@40002400 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			compatible = "st,stm32-lptimer";
+			reg = <0x40002400 0x400>;
+			interrupts-extended = <&exti 23 IRQ_TYPE_EDGE_RISING>;
+			clocks = <&rcc 1 CLK_LPTIMER>;
+			clock-names = "mux";
+			status = "disabled";
+
+			pwm {
+				compatible = "st,stm32-pwm-lp";
+				#pwm-cells = <3>;
+				status = "disabled";
+			};
+
+			trigger@0 {
+				compatible = "st,stm32-lptimer-trigger";
+				reg = <0>;
+				status = "disabled";
+			};
+
+			counter {
+				compatible = "st,stm32-lptimer-counter";
+				status = "disabled";
+			};
+
+			timer {
+				compatible = "st,stm32-lptimer-timer";
+				status = "disabled";
+			};
+		};
+
 		rtc: rtc@40002800 {
 			compatible = "st,stm32-rtc";
 			reg = <0x40002800 0x400>;