Fix static llama AOT tracing (#2800)

Summary:
Fix static llama tracing for MPS backend:

- **AOT** tracing:
```
python3 -m examples.apple.mps.scripts.mps_example --model_name "llama2" --use_partitioner  --no-use_fp16 --checkpoint stories110M.pt --params params.json
```

**Testing:**
AOT:
```
python3 -m examples.apple.mps.scripts.mps_example --model_name "llama2" --use_partitioner  --no-use_fp16 --checkpoint stories110M.pt --params params.json -b
```

Runtime:
```
./cmake-out/examples/apple/mps/mps_executor_runner --model_path ../../pytorch-executorch/executorch/llama2_mps_bundled_fp32.pte --bundled_program --num_runs 0

Output 0: tensor(sizes=[1, 1, 512], [
  0.271252, 0.547134, -0.319407, -0.519001, -0.817092, -0.511795, 1.19794, 0.169265, 0.74455, -0.59659,
  -0.754759, -0.688871, 0.298589, -0.443414, -0.086443, -0.565953, 0.864259, 0.115826, 0.85074, -0.525906,
  0.125811, -0.00499783, -0.463692, 0.29455, -0.910827, 0.539898, -0.958917, -0.160505, 0.345872, -0.33394,
  -0.481556, 1.23247, 0.972564, 1.2528, 0.74983, 0.117909, -0.537549, -0.11374, 0.0533589, -0.724433,
  0.267418, 0.383111, -0.589426, -0.273412, 0.536997, -0.296996, -0.037801, -0.467146, -0.111444, 0.2018,
  0.138447, -0.168977, 0.0633859, -0.147186, 0.162552, -0.340015, -0.481295, -0.285551, -0.486715, 0.266989,
  0.178192, -0.15646, -0.538977, -0.161788, -0.844837, -0.0201809, -0.0330472, -1.00392, -0.683174, -0.352963,
  0.0247648, 0.100644, 0.0750983, 0.617042, -0.0325033, 0.80563, 0.722587, -0.16737, -0.448206, -0.726605,
  0.0371236, -0.340444, 0.0844629, -0.744782, 0.713093, -1.23478, -0.624044, -0.927914, 0.226109, 0.871968,
  -0.181462, 0.737743, 0.630924, 0.352844, 1.22101, -0.433692, -0.545998, 1.25375, 0.604229, 0.567072,
  ...,
  -0.664146, -0.325717, 0.0465028, -0.0638815, -0.414189, -0.0774017, 0.664497, -0.80469, 0.665282, 0.142916,
  -0.136235, -0.181776, -0.0936792, 0.149341, 0.102156, 0.259336, 0.881158, 0.785714, -0.345178, -0.165404,
  0.100859, -0.43653, 0.239712, -0.111407, 0.744646, 0.651979, -0.15812, 0.0528999, 0.699308, 0.0331134,
  -0.102761, -0.0878261, -0.67926, -0.211967, 0.852889, -0.395876, 0.0924324, -0.262803, -0.622059, 0.550099,
  0.162211, -0.531762, 0.0518005, -0.920345, -0.014961, 0.132838, -0.0850867, 0.49853, -1.38389, 1.04421,
  0.220865, 0.160585, -0.239085, -0.745911, 1.19387, -0.597559, -0.722064, 0.267607, 0.65336, -0.360622,
  -0.20821, -0.522872, -0.40434, -0.593412, 0.918845, 1.05659, 0.266254, -0.438084, 0.626653, -0.232121,
  -0.346624, -0.533966, 0.179427, -0.509745, -0.187721, -0.253874, -0.286669, -0.462519, 0.569676, 0.0893508,
  -1.06513, 0.639664, 0.266718, -0.609418, 0.347195, 0.159792, 0.229622, -0.488133, 0.0085784, 0.485227,
  0.0878157, 0.556075, -0.933147, 0.742958, -0.064349, 0.198085, -0.314378, 0.173344, -0.718609, -1.14167,
])
I 00:00:02.547035 executorch:mps_executor_runner.mm:535] Model verified successfully.
```

cc cccclai , shoumikhin

Pull Request resolved: https://github.com/pytorch/executorch/pull/2800

Reviewed By: shoumikhin

Differential Revision: D55615735

Pulled By: cccclai

fbshipit-source-id: 07c86ffbf941e688a7e5c5025aa4587afc260629