[SDPA] Remove private version and only utilize public version (#94004)
# Summary
Due to internal failures we needed to keep the private call in torch.nn.mha. This PR undoes this change, so that we call the public function and remove the private function.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/94004
Approved by: https://github.com/cpuhrsch, https://github.com/albanD
