ARM: dts: stm32: add RNG node for STM32MP13x platforms

The RNG on STM32MP13 offers upgrades like customization of its
configuration and the conditional reset.

The hardware RNG should be managed in the secure world for but it
is supported on Linux. Therefore, is it not default enabled.

Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

Author: GseoC

arch/arm/boot/dts/st/stm32mp131.dtsi

@@ -1221,6 +1221,14 @@
 			status = "disabled";
 		};
 
+		rng: rng@54004000 {
+			compatible = "st,stm32mp13-rng";
+			reg = <0x54004000 0x400>;
+			clocks = <&rcc RNG1_K>;
+			resets = <&rcc RNG1_R>;
+			status = "disabled";
+		};
+
 		mdma: dma-controller@58000000 {
 			compatible = "st,stm32h7-mdma";
 			reg = <0x58000000 0x1000>;