[llvm] [X86] Disable the `vpdpwssd -> vpmaddwd + vpaddd` combiner pattern on AMD Zen4 (PR #84347)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

@bjacob Reopening this - please can you replace the "EnableVPDPWSSTPatterns" with a Tuning flag as suggested on #84182

https://github.com/llvm/llvm-project/pull/84347