ARM: DTS: stm32: add pwrcfg node for stm32f746

This node is needed to enable performance mode
when system frequency is set up to 200Mhz.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Vikas Manocha <vikas.manocha@st.com>
diff --git a/arch/arm/dts/stm32f746.dtsi b/arch/arm/dts/stm32f746.dtsi
index 783d4e7..b95cca2 100644
--- a/arch/arm/dts/stm32f746.dtsi
+++ b/arch/arm/dts/stm32f746.dtsi
@@ -99,12 +99,19 @@
 			status = "disabled";
 			u-boot,dm-pre-reloc;
 		};
+
+		pwrcfg: power-config@58024800 {
+			compatible = "syscon";
+			reg = <0x40007000 0x400>;
+		};
+
 		rcc: rcc@40023810 {
 			#reset-cells = <1>;
 			#clock-cells = <2>;
 			compatible = "st,stm32f42xx-rcc", "st,stm32-rcc";
 			reg = <0x40023800 0x400>;
 			clocks = <&clk_hse>;
+			st,syscfg = <&pwrcfg>;
 			u-boot,dm-pre-reloc;
 		};