[TPU] Rename path to tpu platform (#28452)

Signed-off-by: Kyuyeun Kim <kyuyeunk@google.com>

vllm/platforms/__init__.py

@@ -38,7 +38,7 @@ def tpu_platform_plugin() -> str | None:
     # Check for Pathways TPU proxy
     if envs.VLLM_TPU_USING_PATHWAYS:
         logger.debug("Confirmed TPU platform is available via Pathways proxy.")
-        return "tpu_inference.platforms.tpu_jax.TpuPlatform"
+        return "tpu_inference.platforms.tpu_platform.TpuPlatform"
 
     # Check for libtpu installation
     try: