[docs] update input documentation for MAMBA2 and MISTRAL models to include cache_position and attention_mask details (#34322)
* [docs] update input documentation for MAMBA2 and MISTRAL models to include cache_position and attention_mask details
* [docs] correct input documentation for MISTRAL model to reference `input_ids` instead of `decoder_input_ids`
* [docs] clarify cache_position description in MISTRAL model documentation