[vulkan][op] add.Scalar, mul.Scalar (#42674)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/42674
Test Plan: Imported from OSS
Reviewed By: AshkanAliabadi
Differential Revision: D22978763
Pulled By: IvanKobzarev
fbshipit-source-id: 9fd97d394205e3fa51992ee99d5bfafc33f75efa
