[llvm] Adjust files including llvm/Support/Endian.h (NFC)

llvm/include/llvm/Support/VersionTuple.h doesn't need anything from
llvm/Support/Endian.h, but llvm/lib/DebugInfo/BTF/BTFParser.cpp relies
on a transitive inclusion of llvm/Support/Endian.h.

Author: kazutakahirata

llvm/include/llvm/Support/VersionTuple.h

@@ -16,7 +16,6 @@
 
 #include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/Hashing.h"
-#include "llvm/Support/Endian.h"
 #include <optional>
 #include <string>
 #include <tuple>

llvm/lib/DebugInfo/BTF/BTFParser.cpp

@@ -13,6 +13,7 @@
 
 #include "llvm/DebugInfo/BTF/BTFParser.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/Endian.h"
 #include "llvm/Support/Errc.h"
 
 #define DEBUG_TYPE "debug-info-btf-parser"