add "mm_spatial_pool_mode" to config.

"mm_spatial_pool_mode" is still a configuration, similar to the llava_next_video.

config.json

@@ -153,6 +153,7 @@
   "image_token_index": 151646,
   "model_type": "llava_onevision",
   "projector_hidden_act": "gelu",
+  "mm_spatial_pool_mode": "bilinear",
   "text_config": {
     "_name_or_path": "Qwen/Qwen2-7B-Instruct",
     "architectures": [