[mlir][linalg] Remove unused payload related OutOpOperand

Some higher level operations such as torch.max generates linalg generic
that returns both the index and the value of the max operation. However
sometimes not all information is being used. This however blocks
vectorization for certain cases which causes performance degradation.
This patch aims to fix this issue.

Reviewed By: mravishankar

Differential Revision: https://reviews.llvm.org/D135388