[vulkan] Efficient gemm implementation (#49609)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/49609
Test Plan: Imported from OSS
Reviewed By: AshkanAliabadi
Differential Revision: D26209677
Pulled By: SS-JIA
fbshipit-source-id: 773a944559bf0deb3cf3e233d833220a12f9f2ab
