[ROCM] bugfix for arg_min_max (#36098)

paddle/fluid/operators/arg_min_max_op_base.cu.h

@@ -89,22 +89,25 @@ void ComputeFullArg(const platform::CUDADeviceContext& ctx, const Tensor& input,
                     const int64_t n) {
   auto cu_stream = ctx.stream();
   auto ComputeBlockSize = [](int64_t col) {
+    auto block_size = 8;
     if (col > 512)
-      return 1024;
+      block_size = 1024;
     else if (col > 256)
-      return 512;
+      block_size = 512;
     else if (col > 128)
-      return 256;
+      block_size = 256;
     else if (col > 64)
-      return 128;
+      block_size = 128;
     else if (col > 32)
-      return 64;
+      block_size = 64;
     else if (col > 16)
-      return 32;
+      block_size = 32;
     else if (col > 8)
-      return 16;
-    else
-      return 8;
+      block_size = 16;
+#ifdef __HIPCC__
+    block_size = std::min(block_size, 256);
+#endif
+    return block_size;
   };
 
   int64_t max_grid_dimx = ctx.GetCUDAMaxGridDimSize().x;