[Doc][NFC] Update links to CI status badges (#5869)

Fix updated workflow name in README.md and use new style links with IDs instead of names to avoid this kind of issue in future.

Author: Alexander Batashev

README.md

@@ -10,8 +10,8 @@ Intel LLVM-based projects:
 
 [![](https://spec.oneapi.io/oneapi-logo-white-scaled.jpg)](https://www.oneapi.io/)
 
-[![Linux Post Commit Checks](https://github.com/intel/llvm/workflows/Linux%20Post%20Commit%20Checks/badge.svg)](https://github.com/intel/llvm/actions?query=workflow%3A%22Linux+Post+Commit+Checks%22)
-[![Generate Doxygen documentation](https://github.com/intel/llvm/workflows/Generate%20Doxygen%20documentation/badge.svg)](https://github.com/intel/llvm/actions?query=workflow%3A%22Generate+Doxygen+documentation%22)
+[![SYCL Post Commit](https://github.com/intel/llvm/actions/workflows/sycl_post_commit.yml/badge.svg?branch=sycl)](https://github.com/intel/llvm/actions/workflows/sycl_post_commit.yml)
+[![Generate Doxygen documentation](https://github.com/intel/llvm/actions/workflows/gh_pages.yml/badge.svg?branch=sycl)](https://github.com/intel/llvm/actions/workflows/gh_pages.yml)
 
 The Data Parallel C++ or DPC++ is a LLVM-based compiler project that implements
 compiler and runtime support for the SYCL\* language. The project is hosted in