Revert "musa: update compile flags (ggml-org#16265)"

This reverts commit 91a2a56.

Author: Nexesenex

ggml/src/ggml-cuda/fattn-vec.cuh

@@ -535,6 +535,8 @@ void ggml_cuda_flash_attn_ext_vec_case(ggml_backend_cuda_context & ctx, ggml_ten
     float logit_softcap;
     memcpy(&logit_softcap, (const float *) KQV->op_params + 2, sizeof(float));
 
+    const int cc = ggml_cuda_info().devices[ggml_cuda_get_device()].cc;
+
     if (Q->ne[1] == 1) {
         constexpr int cols_per_block = 1;
         if (logit_softcap == 0.0f) {