[llvm-exegesis] Move libpfm linking to LLVMExegesis.

Summary: This patch moves linking of libpfm from different places to a single one.

Reviewers: courbet

Subscribers: mgorny, tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D48075

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334499 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed