Adds GQA support for SDPA op.
Adds GQA support for SDPA op.

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/11644 from shawnwang18:shawnw/move_cublaslt_creation_to_thunk_init 1d9b36f31fa8dbfce6f628065e946b3219148757
