[llvm] [benchmark] Support Linux/sparc64 /proc/cpuinfo (PR #125503)

[Brad Smith via llvm-commits]

brad0 wrote:

@mtrofin  Someone else already submitted a better diff to take care of this by ripping out all the /proc/cpuinfo parsing and using a portable method like every other OS.. https://github.com/google/benchmark/commit/c24774dc4f4402c3ad150363321cc972ed2669e7

https://github.com/llvm/llvm-project/pull/125503