Fix Step3.7 vision RoPE spatial W/H axis order (#50547)

* Fix Step3.7 vision RoPE spatial axis order

* Remove synthetic RoPE unit test

---------

Co-authored-by: QuKa <caohongchen.chc@antgroup.com>

Author: caohch-1

src/transformers/models/step3p7/modeling_step3p7.py

@@ -603,8 +603,8 @@ def recomposition_frequencies(self, freq):
         """
         Recompose the frequencies into the final spatial layout used per each grid.
         """
-        freq_hw = freq.flatten(1)
-        return torch.cat((freq_hw, freq_hw), dim=-1)
+        freq_wh = freq.flip(1).flatten(1)
+        return torch.cat((freq_wh, freq_wh), dim=-1)
 
 
 class Step3p7VisionMLP(MiniMaxM3VLVisionMLP):