[mlir][linalg] Propagate filter tensor encoding in im2col (#160099)
In the im2col decomposition, propagate the filter tensor encoding (if
specified) through the tensor.collapse_shape op, so that it can be used
by the consuming linalg.generic matmul op.
Signed-off-by: Fabrizio Indirli <Fabrizio.Indirli@arm.com>