feat: Add watsonx inference adapter (#1895)

# What does this PR do?
IBM watsonx ai added as the inference [#1741
](https://github.com/meta-llama/llama-stack/issues/1741)

[//]: # (If resolving an issue, uncomment and update the line below)
[//]: # (Closes #[issue-number])

---------

Co-authored-by: Sajikumar JS <sajikumar.js@ibm.com>

llama_stack/providers/remote/inference/watsonx/config.py

@@ -0,0 +1,46 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+import os
+from typing import Any, Dict, Optional
+
+from pydantic import BaseModel, Field, SecretStr
+
+from llama_stack.schema_utils import json_schema_type
+
+
+class WatsonXProviderDataValidator(BaseModel):
+    url: str
+    api_key: str
+    project_id: str
+
+
+@json_schema_type
+class WatsonXConfig(BaseModel):
+    url: str = Field(
+        default_factory=lambda: os.getenv("WATSONX_BASE_URL", "https://us-south.ml.cloud.ibm.com"),
+        description="A base url for accessing the watsonx.ai",
+    )
+    api_key: Optional[SecretStr] = Field(
+        default_factory=lambda: os.getenv("WATSONX_API_KEY"),
+        description="The watsonx API key, only needed of using the hosted service",
+    )
+    project_id: Optional[str] = Field(
+        default_factory=lambda: os.getenv("WATSONX_PROJECT_ID"),
+        description="The Project ID key, only needed of using the hosted service",
+    )
+    timeout: int = Field(
+        default=60,
+        description="Timeout for the HTTP requests",
+    )
+
+    @classmethod
+    def sample_run_config(cls, **kwargs) -> Dict[str, Any]:
+        return {
+            "url": "${env.WATSONX_BASE_URL:https://us-south.ml.cloud.ibm.com}",
+            "api_key": "${env.WATSONX_API_KEY:}",
+            "project_id": "${env.WATSONX_PROJECT_ID:}",
+        }