change view to reshape to support channels last

[chunyuan-w]

The current implementation of drq does not support channels last input since view has constraints on the input size and stride (https://pytorch.org/docs/stable/generated/torch.Tensor.view.html):

Cannot view a tensor with shape torch.Size([1, 32, 35, 35]) and strides (39200, 1, 1120, 32) as a tensor with shape (1, 39200)!

Change view to reshape which returns a view if the shapes are compatible, and copies (equivalent to calling contiguous()) otherwise.