Update flag message

Author: pgorlani

clang/include/clang/Driver/Options.td

@@ -987,7 +987,7 @@ defm cuda_prec_sqrt : BoolFOption<"cuda-prec-sqrt",
   BothFlags<[], " that sqrt is correctly rounded (for CUDA devices)">>;
 defm nvvm_cuda_approx_tanhf : BoolFOption<"cuda-approx-tanhf",
   TargetOpts<"NVVMCudaApproxTanhf">, DefaultFalse,
-  PosFlag<SetTrue, [CC1Option], "Use the built-in fast approximation of tanhf function. Device needs to have a compute capability >= 8.0">,
+  PosFlag<SetTrue, [CC1Option], "Only SYCL. Use the built-in fast approximation of tanhf function. Device needs to have a compute capability >= 8.0">,
   NegFlag<SetFalse>>;
 def rocm_path_EQ : Joined<["--"], "rocm-path=">, Group<i_Group>,
   HelpText<"ROCm installation path, used for finding and automatically linking required bitcode libraries.">;