update comment

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@203859 91177308-0d34-0410-b5e6-96231b3b80d8
[cmake] There is only one PoCC file, and this is in /Transforms

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@203861 91177308-0d34-0410-b5e6-96231b3b80d8