Update docs for torch.real to indicate that it's supported for real tensors (#71962)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/71962
Test Plan: Imported from OSS
Reviewed By: davidberard98
Differential Revision: D33846613
Pulled By: anjali411
fbshipit-source-id: a9782bf4e8a7f3ae1fcd4f7ff558ba80b6af012c
(cherry picked from commit 93ea37800ffaae9cd4e085f7d963ad5fc8ce78fa)
