[HIP] Fix -gsplit-dwarf option

when -gsplit option is used with clang driver, clang driver will create
a filename with .dwo option based on the input file name and pass
it to clang -cc1. This file is used for storing the debug info. Since
HIP generate separate object files for different GPU arch's,
this file should be different for different GPU arch. This patch
adds _ and GPU arch to the stem of the dwo file.

Differential Revision: https://reviews.llvm.org/D87791