[clang] [amdgpu-arch] Replace use of HSA with reading sysfs directly (PR #116651)

[via cfe-commits]

b-sumner wrote:

I feel like this is a workaround.  Can we not fix the "limitation of the driver" and if there is an issue with HSA overhead, shouldn't we file a ticket?

https://github.com/llvm/llvm-project/pull/116651