Revert D25763758: [pytorch][PR] introduce a flag to disable aten::cat in TE
Test Plan: revert-hammer
Differential Revision:
D25763758 (https://github.com/pytorch/pytorch/commit/9e0b4a96e48132190220820684033a77a92e8a33)
Original commit changeset: c4f4a8220964
fbshipit-source-id: 98775ad9058b81541a010e646b0cf4864854be3e
