[CMake] Remove lldb-server from LLDB.framework

Summary: The LLDB test suite doesn't need lldb-server in the framework bundle anymore.

Reviewers: JDevlieghere, jasonmolenda, xiaobai

Reviewed By: JDevlieghere

Subscribers: mgorny, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D62474

llvm-svn: 361947