[Doc] Update Granite model docs (vllm-project#9025)

Signed-off-by: Alvant <[email protected]>

Author: njhill

docs/source/models/supported_models.rst

@@ -92,8 +92,12 @@ Decoder-only Language Models
     - :code:`EleutherAI/gpt-neox-20b`, :code:`EleutherAI/pythia-12b`, :code:`OpenAssistant/oasst-sft-4-pythia-12b-epoch-3.5`, :code:`databricks/dolly-v2-12b`, :code:`stabilityai/stablelm-tuned-alpha-7b`, etc.
     -
   * - :code:`GraniteForCausalLM`
-    - Granite, Power-LM
-    - :code:`ibm/granite-7b-base`, :code:`ibm/PowerLM-3b` etc.
+    - PowerLM
+    - :code:`ibm/PowerLM-3b` etc.
+    - ✅︎
+  * - :code:`GraniteMoeForCausalLM`
+    - PowerMoE
+    - :code:`ibm/PowerMoE-3b` etc.
     - ✅︎
   * - :code:`InternLMForCausalLM`
     - InternLM