[Model] Support for Spark2_5ForCausalLM implementation (#27868)

* Add Spark3 Model
* rename spark3 -> spark2_5

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@huggingface.co>
Co-authored-by: dongjiang <dongjiang2010@gmail.com>

conversion/base.py

@@ -1543,6 +1543,9 @@ class TextModel(ModelBase):
         if chkhsh == "9e454714343b69b99b71795c1d27a68c2a1d15dab111f4d353109f966af29da7":
             # ref: https://huggingface.co/LiquidAI/LFM2.5-8B-A1B
             res = "lfm2"
+        if chkhsh == "0a766d034107bc736a3f2dc4968fd62e54a3570f1454443e0c5a4cc6bd7941ed":
+            # ref: https://huggingface.co/XHToken/Spark-X2.5-1.7B
+            res = "spark2_5"
         if chkhsh == "0ef9807a4087ebef797fc749390439009c3b9eda9ad1a097abbe738f486c01e5":
             # ref: https://huggingface.co/meta-llama/Meta-Llama-3-8B
             res = "llama-bpe"