ARM: dts: AM33xx: Add RNG node

Add the AM33xx RNG module's device tree data.
Also add Documentation file describing the data
for the RNG module.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/boot/dts/am33xx.dtsi b/arch/arm/boot/dts/am33xx.dtsi
index 9ae258e..fcb9c8e 100644
--- a/arch/arm/boot/dts/am33xx.dtsi
+++ b/arch/arm/boot/dts/am33xx.dtsi
@@ -779,5 +779,12 @@
 				<&edma 11>;
 			dma-names = "tx", "rx";
 		};
+
+		rng: rng@48310000 {
+			compatible = "ti,omap4-rng";
+			ti,hwmods = "rng";
+			reg = <0x48310000 0x2000>;
+			interrupts = <111>;
+		};
 	};
 };