ObsoleteFiles: remove duplicated and incorrect libclang_rt powerpc64le entries

PR: 273776
Approved by: re (gjb)
MFC after: 3 days

(cherry picked from commit e2d3168d1207561df2e1cf0a2a8d13c198e5f8d3)
(cherry picked from commit 2d5eb9b95a9d99c0a80994fc932f6ad0589f69ed)