Move llvmc2 header files under include/llvm/CompilerDriver

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56466 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvmc2/Plugin.cpp b/tools/llvmc2/Plugin.cpp
index 70d9987..cd94a01 100644
--- a/tools/llvmc2/Plugin.cpp
+++ b/tools/llvmc2/Plugin.cpp
@@ -11,7 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "Plugin.h"
+#include "llvm/CompilerDriver/Plugin.h"
 
 #include <vector>