[Relay][Pytorch] Add support for aten::scaled_dot_product_attention

[mshr-h]

Fix #15361
Support torch.nn.functional.scaled_dot_product_attention and torch.nn.Transformer.
cc @jikechao @vvchernov @Hzfengsy @masahi

[HPC4AI]

May I ask which version of tvm I need to use and how to use tvm to accelerate the sdpa operator?

Fix #15361 Support torch.nn.functional.scaled_dot_product_attention and torch.nn.Transformer. cc @jikechao @vvchernov @Hzfengsy @masahi

[mshr-h]

@FuncJ
You need v0.15 which will be released on Jan 22. #16277

[yogurfrul]

I worked on torch2.1. The testcase verify_model(test_fn(), [query_4d, key_3d, value_4d]) got error as below:
IndexError: Dimension out of range (expected to be in range of [-3, 2], but got 3)