[clang-tools-extra] [cmake] Use add_clang_tool() to install tools

Replace add_clang_executable() calls with add_clang_tool() that takes
care of creating correct, distribution-friendly install target.  While
at it, remove redundant install calls.

This change also causes clang-move and pp-trace to be installed.

Differential Revision: https://reviews.llvm.org/D68423

llvm-svn: 373694