Aaron En Ye Shi
7fb914e4d6
Linux Pro build uses the LLVM_ROOT variable to
specify where llvm is located. We must use a different
name, HIP_LLVM_ROOT for LLVM's prefix location.
Change-Id: I28baf8672217a438a5dd45829d9af04b3553f615
[ROCm/hip commit: 93b9384529]