Update README.md

Accept version fix.

Co-authored-by: Frederic Pillon <[email protected]>
Signed-off-by: Kazuki Ota <[email protected]>

Author: dojyorin

README.md

@@ -540,7 +540,7 @@ User can add a STM32 based board following this [wiki](https://github.com/stm32d
 
 | Status | Device(s) | Name | Release | Notes |
 | :----: | :-------: | ---- | :-----: | :---- |
-| :yellow_heart:  | STM32H503KB | Generic Board | *2.9.0* |  |
+| :yellow_heart:  | STM32H503KB | Generic Board | **2.8.1** |  |
 | :green_heart:  | STM32H503RB | Generic Board | *2.7.0* |  |
 | :green_heart:  | STM32H563IIKxQ | Generic Board | *2.6.0* |  |
 | :green_heart:  | STM32H563ZG<br>STM32H563ZI | Generic Board | *2.6.0* |  |