ThriftCppLibrary.cmake: fixup deps
ThriftCppLibrary.cmake: fixup deps

Summary:
this adds the include and library dirs for generated thrift targets;
these are important when those dependencies are not installed into a default
prefix.

Reviewed By: strager

Differential Revision: D14683957

fbshipit-source-id: ed47ffac5c8732810afe77e6947584b7a2f05155

rsocket/rsocket-cpp,rsocket/rsocket-cpp,ReactiveSocket/reactivesocket-cpp,ReactiveSocket/reactivesocket-cpp,ReactiveSocket/reactivesocket-cpp,rsocket/rsocket-cpp,phoad/rsocket-cpp,phoad/rsocket-cpp,rsocket/rsocket-cpp,phoad/rsocket-cpp,phoad/rsocket-cpp,phoad/rsocket-cpp