DMA: Freescale: move functions to avoid forward declarations

These functions will be modified in the next patch in the series. By moving the
function in a patch separate from the changes, it will make review easier.

Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: Qiang Liu <qiang.liu@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>