add custom ops to buck oss (#2712)

Summary:

Add to oss llama runner for buck

Reviewed By: cccclai, kirklandsign

Differential Revision: D55406619

Author: lucylq

examples/models/llama2/runner/targets.bzl

@@ -4,7 +4,7 @@ def _get_operator_lib(aten = False):
     if aten:
         return ["//executorch/kernels/aten:generated_lib_aten"]
     elif runtime.is_oss:
-        return ["//executorch/kernels/portable:generated_lib"]
+        return ["//executorch/kernels/portable:generated_lib", "//executorch/examples/models/llama2/custom_ops:custom_ops"]
     else:
         return ["//executorch/configurations:optimized_native_cpu_ops", "//executorch/examples/models/llama2/custom_ops:custom_ops", "//executorch/examples/models/llama2/ops:generated_lib"]