dmaengine: mpc512x: Split device_control

Split the device_control callback of the Freescale MPC512x DMA driver to make
use of the newly introduced callbacks, that will eventually be used to retrieve
slave capabilities.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --cc drivers/dma/mpc512x_dma.c
Simple merge