[MPS] Fall back multi-layer LSTM on macOS 12 (#90909)
The native implementation of LSTM has been fixed on macOS 13.
On macOS 12, the multi-layer LSTM still has a numerical correctness issue that cannot be resolved on OS's side.
Thus, we fall back the multi-layer LSTM on macOS 12 to LSTMCell iteration. It might have performance impact but will make LSTM on macOS 12 fully usable.
Fixes: #90421
Issues related: #80306, #83144
Pull Request resolved: https://github.com/pytorch/pytorch/pull/90909
Approved by: https://github.com/albanD, https://github.com/kulinseth