Update the model type to make it compatible with mlx-lm's model mapping.

config.json

@@ -16,7 +16,7 @@
   "img_processor": null,
   "initializer_range": 0.02,
   "layer_norm_epsilon": 1e-05,
-  "model_type": "phi-msft",
+  "model_type": "phixtral",
   "n_embd": 2560,
   "n_head": 32,
   "n_head_kv": null,

configuration_phi.py

@@ -10,7 +10,7 @@ from transformers import PretrainedConfig
 class PhiConfig(PretrainedConfig):
     """Phi configuration."""
 
-    model_type = "phi-msft"
+    model_type = "phixtral"
     attribute_map = {
         "max_position_embeddings": "n_positions",
         "hidden_size": "n_embd",