[clang] [clang][doc][SYCL] Expand SYCL driver release notes (PR #200449)

[Mariya Podchishchaeva via cfe-commits]

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@@ -945,10 +945,36 @@ OpenMP Support
 
 SYCL Support
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+- Initial SYCL offload compilation support has been added to Clang. The
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Fznamznon wrote:

I think this has been added long time ago. The release notes often represent the diff between clang release version. I think current version is clang 23 which is coming out soon and previous is clang 22 which came out in winter.

https://github.com/llvm/llvm-project/pull/200449