[llvm] Add llvm-lipo dependency to runtimes

Summary: Currently, llvm-lipo is not specified as a dependency, but it is needed when building Darwin-x86_64 runtimes, so I'm adding it to the dependencies lists.

Reviewers: alexshap, beanz, phosek, compnerd, smeenai, mtrent, plotfi, xiaobai

Reviewed By: phosek, smeenai

Subscribers: smeenai, mgorny, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71429