This patch adds support for DMA_SLAVE_CONFIG in dwc DMAC controller. Fields in
struct dw_dma_slave for passing similar data are preserved in this patch untill
all existing users are fixed.

That will be handled later in this patchset.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>