Replace Synopsys link with blackduck one to solve link error.

Author: ActoryOu

test/Coverity/README.md

@@ -13,7 +13,7 @@ see the [MISRA.md](https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/blob/main/MISRA
 
 ## Getting Started
 ### Prerequisites
-You can run this on a platform supported by Coverity. The list and other details can be found [here](https://sig-docs.synopsys.com/polaris/topics/c_coverity-compatible-platforms.html).
+You can run this on a platform supported by Coverity. The list and other details can be found [here](https://documentation.blackduck.com/bundle/coverity-docs/page/deploy-install-guide/topics/supported_platforms_for_coverity_analysis.html).
 To compile and run the Coverity target successfully, you must have the following:
 
 1. CMake version > 3.13.0 (You can check whether you have this by typing `cmake --version`)