[CMake] Add LLVM_TOOLS_INSTALL_DIR to LLVMConfig.cmake

This is the more-correct fix to out-of-tree building. AddLLVM.cmake relies on this variable being set, so we should make sure it is set in LLVMConfig.cmake.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272279 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed