fsl/fman: remove unnecessary set_dma_ops() call and HAS_DMA dependency

The platform device is no longer used for DMA mapping so the
(questionable) setting of the DMA ops done here is no longer
needed. Removing it together with the HAS_DMA dependency that
it required.

Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>