[clang][codegen] Annotate `correctly-rounded-divide-sqrt-fp-math` fn-attr for OpenCL only.

- `-cl-fp32-correctly-rounded-divide-sqrt` is an OpenCL-specific option
  and `correctly-rounded-divide-sqrt-fp-math` should be added for OpenCL
  at most.

Differential revision: https://reviews.llvm.org/D88303