[gn build] Port df323ba

Author: llvmgnsyncbot

llvm/utils/gn/secondary/llvm/lib/Target/X86/BUILD.gn

@@ -117,7 +117,6 @@ static_library("LLVMX86CodeGen") {
     "X86OptimizeLEAs.cpp",
     "X86PadShortFunction.cpp",
     "X86PartialReduction.cpp",
-    "X86PreAMXConfig.cpp",
     "X86PreTileConfig.cpp",
     "X86RegisterBankInfo.cpp",
     "X86RegisterInfo.cpp",