Add missing dependency

Spotted by Ninja.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139129 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/CMakeLists.txt b/lib/Frontend/CMakeLists.txt
index 556b133..2807296 100644
--- a/lib/Frontend/CMakeLists.txt
+++ b/lib/Frontend/CMakeLists.txt
@@ -48,5 +48,6 @@
   ClangDiagnosticFrontend 
   ClangDiagnosticLex
   ClangDiagnosticSema
+  ClangDriverOptions
   ClangDeclNodes
   ClangStmtNodes)