ARM: dts: stm32mp1: DT alignment with Linux kernel v5.8-rc1

DT alignment with Linux kernel v5.8-rc1 for the STM32MP15x soc
device tree files and the STMicroelectronics boards device tree files.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/arch/arm/dts/stm32mp15-u-boot.dtsi b/arch/arm/dts/stm32mp15-u-boot.dtsi
index 66be7df..42e2e2e 100644
--- a/arch/arm/dts/stm32mp15-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp15-u-boot.dtsi
@@ -32,6 +32,10 @@
 
 	reboot {
 		u-boot,dm-pre-reloc;
+		compatible = "syscon-reboot";
+		regmap = <&rcc>;
+		offset = <0x404>;
+		mask = <0x1>;
 	};
 
 	soc {