Update on "Use llm_config instead of args in export_llama functions"

Differential Revision: [D75484927](https://our.internmc.facebook.com/intern/diff/D75484927)

[ghstack-poisoned]

Author: jackzhxng

examples/models/llama/config/llm_config.py

@@ -470,7 +470,7 @@ class LlmConfig:
     backend: BackendConfig = field(default_factory=BackendConfig)
 
     @classmethod
-    def from_args(args: argparse.Namespace) -> "LlmConfig":  # noqa: C901
+    def from_args(cls, args: argparse.Namespace) -> "LlmConfig":  # noqa: C901
         """
         To support legacy purposes, this function converts CLI args from
         argparse to an LlmConfig, which is used by the LLM export process.