add test model

Author: ngxson

tools/mtmd/tests.sh

@@ -69,6 +69,7 @@ add_test_vision "ggml-org/InternVL2_5-1B-GGUF:Q8_0"
 add_test_vision "ggml-org/InternVL3-1B-Instruct-GGUF:Q8_0"
 add_test_vision "ggml-org/Qwen2.5-Omni-3B-GGUF:Q4_K_M"
 add_test_vision "ggml-org/LFM2-VL-450M-GGUF:Q8_0"
+add_test_vision "ggml-org/granite-docling-258M-GGUF:Q8_0"
 
 add_test_audio  "ggml-org/ultravox-v0_5-llama-3_2-1b-GGUF:Q8_0"
 add_test_audio  "ggml-org/Qwen2.5-Omni-3B-GGUF:Q4_K_M"