ggml : fix multi-threaded clamp_f32 (ggml-org#11824)

* Bug fix for clamp_f32

When using tensors larger than 1d clamp operation does not work due to the restriction of returning if ith is not 0.

* Bug fix for clamp_f32

* Bug fix for clamp_f32

Author: Burton2000

ggml/src/ggml-cpu/ggml-cpu.c

@@ -9074,10 +9074,6 @@ static void ggml_compute_forward_clamp_f32(
 
     const struct ggml_tensor * src0 = dst->src[0];
 
-    if (params->ith != 0) {
-        return;
-    }
-
     float min;
     float max;
     memcpy(&min, (float *) dst->op_params + 0, sizeof(float));