Update mkl to 2020.2.254 (#52964)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/52907
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52964
Reviewed By: H-Huang
Differential Revision: D26726464
Pulled By: seemethere
fbshipit-source-id: 8f3067292e6416e299b4b040c8fb73510134f02e
