Summary:
This changes allows to disable or use customized libxml2 for lldb.
1. Removes redundant include_directories. The one in LLDBConfig.cmake should be enough.
2. Link to ${LIBXML2_LIBRARIES} if xml2 is enabled.
Subscribers: mgorny, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D80257