text: Title: ModelSummary does not account for every type of precision strings
  Body: ### Bug description
  
  The `precision_to_bits` dictionary in https://github.com/Lightning-AI/pytorch-lightning/blob/master/src/lightning/pytorch/utilities/model_summary/model_summary.py#L219 does not account for every type of precision, e.g., `bf16-true`.
  
  This will fail in getting the proper key from the dictionary and will default to 32. 
  
  ### What version are you seeing the problem on?
  
  v2.5, master
  
  ### How to reproduce the bug
  
  In `lightning/pytorch/utilities/model_summary/model_summary.py:L219`, just add the following when `self._model.trainer.precision="bf16-true"`:
  
  ```python
  ...
  precision_to_bits = {"64": 64, "32": 32, "16": 16, "bf16": 16}
  print(precision_to_bits.get(self._model.trainer.precision, 32))
  raise
  ...
  ```
  
  ### Error messages and logs
  
  ```
  # Error messages and logs here please
  ```
  
  
  ### Environment
  
  <details>
    <summary>Current environment</summary>
  
  ```
  #- PyTorch Lightning Version (e.g., 2.5.0): master
  #- PyTorch Version (e.g., 2.5): 2.5.1
  #- Python version (e.g., 3.12): 3.10
  #- OS (e.g., Linux): Ubuntu 22.04
  #- CUDA/cuDNN version: 12.4
  #- GPU models and configuration: 4xNVIDIA H100 NVL
  #- How you installed Lightning(`conda`, `pip`, source): pip
  ```
  
  </details>
  
  
  ### More info
  
  _No response_