[clang-sycl-linker][NFC] Remove dead includes (#161564)

These includes are not used by ClangSYCLLinker.cpp directly.
Explicitly include FormatVariadic.h for formatv declaration, which was implicitly included by removed headers.

Author: bader

clang/tools/clang-sycl-linker/ClangSYCLLinker.cpp

@@ -27,22 +27,16 @@
 #include "llvm/LTO/LTO.h"
 #include "llvm/Linker/Linker.h"
 #include "llvm/MC/TargetRegistry.h"
-#include "llvm/Object/Archive.h"
-#include "llvm/Object/ArchiveWriter.h"
 #include "llvm/Object/Binary.h"
-#include "llvm/Object/ELFObjectFile.h"
 #include "llvm/Object/IRObjectFile.h"
-#include "llvm/Object/ObjectFile.h"
 #include "llvm/Object/OffloadBinary.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Option/OptTable.h"
 #include "llvm/Option/Option.h"
-#include "llvm/Remarks/HotnessThresholdParser.h"
 #include "llvm/Support/CommandLine.h"
-#include "llvm/Support/FileOutputBuffer.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/InitLLVM.h"
-#include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Program.h"
 #include "llvm/Support/Signals.h"