boards: arm: stm32h747i_disco: rng

add rng driver support

Signed-off-by: Alexander Kozhinov <AlexanderKozhinov@yandex.com>
diff --git a/boards/arm/stm32h747i_disco/doc/index.rst b/boards/arm/stm32h747i_disco/doc/index.rst
index 4f47c15..a7b6043 100644
--- a/boards/arm/stm32h747i_disco/doc/index.rst
+++ b/boards/arm/stm32h747i_disco/doc/index.rst
@@ -65,6 +65,8 @@
 +-----------+------------+-------------------------------------+
 | ETHERNET  | on-chip    | ethernet  (*)                       |
 +-----------+------------+-------------------------------------+
+| RNG       | on-chip    | True Random number generator        |
++-----------+------------+-------------------------------------+
 
 (*) From UM2411 Rev 4:
    With the default setting, the Ethernet feature is not working because of
diff --git a/boards/arm/stm32h747i_disco/stm32h747i_disco_m7.dts b/boards/arm/stm32h747i_disco/stm32h747i_disco_m7.dts
index 81f55e1..ff2ec85 100644
--- a/boards/arm/stm32h747i_disco/stm32h747i_disco_m7.dts
+++ b/boards/arm/stm32h747i_disco/stm32h747i_disco_m7.dts
@@ -70,3 +70,7 @@
 		     &eth_txd0_pg13
 		     &eth_txd1_pg12>;
 };
+
+&rng {
+	status = "okay";
+};