Revert D33136054: Remove backward ops for miopen convolution
Test Plan: revert-hammer
Differential Revision:
D33136054 (https://github.com/pytorch/pytorch/commit/8b9b819d22bbf003d5b9cf95f6f04653df17b6ea)
Original commit changeset: e049168732bd
Original Phabricator Diff: D33136054 (https://github.com/pytorch/pytorch/commit/8b9b819d22bbf003d5b9cf95f6f04653df17b6ea)
fbshipit-source-id: 2a3cc3df3519d04595795f0bc87a807705d13a13
