[HIP] add --offload-add-rpath

Add an option --[no-]offload-add-rpath to control whether to
pass -rpath to linker for HIP runtime library. By default it
is off to match gcc/clang behavior for not adding -rpath
for runtime library by default.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D136854