doc: release-notes-4.0: add release notes for USB

Add release notes for USB support.

Signed-off-by: Johann Fischer <[email protected]>

Author: jfischer-no

doc/releases/release-notes-4.0.rst

@@ -717,6 +717,8 @@ Drivers and Sensors
 * USB
 
   * Added support for USB HS on STM32U59x/STM32U5Ax SoC variants.
+  * Enhanced DWC2 UDC driver
+  * Added UDC drivers for Smartbond, NuMaker USBD and RP2040 device controllers
 
 * Video
 
@@ -1017,6 +1019,13 @@ Networking
 USB
 ***
 
+* New USB device stack:
+
+  * Added USB CDC Network Control Model implementation
+  * Enhanced USB Audio class 2 implementation
+  * Made USB device stack high-bandwidth aware
+  * Enhanced CDC ACM and HID class implementations
+
 Devicetree
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