[LLDB][MIPS] Debug bare-iron targets lacking support for qC /qfThreadInfo

    SUMMARY:
    Using response.IsUnsupportedResponse instead of !response.IsNormalResponse().

    Reviewers: clayborg, labath
    Subscribers: nitesh.jain, mohit.bhakkad, sagar, bhushan and lldb-commits
    Differential Revision: http://reviews.llvm.org/D12876

llvm-svn: 247968