ARM: dts: stm32: Add compatibles for syscon for stm32h743

Syscon nodes needs at least 2 compatibles to be compliant why yaml documentation.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32h743.dtsi

@@ -361,8 +361,8 @@ exti: interrupt-controller@58000000 {
 			interrupts = <1>, <2>, <3>, <6>, <7>, <8>, <9>, <10>, <23>, <40>, <41>, <62>, <76>;
 		};
 
-		syscfg: system-config@58000400 {
-			compatible = "syscon";
+		syscfg: syscon@58000400 {
+			compatible = "st,stm32-syscfg", "syscon";
 			reg = <0x58000400 0x400>;
 		};
 
@@ -501,7 +501,7 @@ rcc: reset-clock-controller@58024400 {
 		};
 
 		pwrcfg: power-config@58024800 {
-			compatible = "syscon";
+			compatible = "st,stm32-power-config", "syscon";
 			reg = <0x58024800 0x400>;
 		};