dmaengine/dw_dmac: Add support for DMA_SLAVE_CONFIG

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: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h
index 5eef694..2005d30 100644
--- a/drivers/dma/dw_dmac_regs.h
+++ b/drivers/dma/dw_dmac_regs.h
@@ -153,6 +153,9 @@
 	struct dw_cyclic_desc	*cdesc;
 
 	unsigned int		descs_allocated;
+
+	/* configuration passed via DMA_SLAVE_CONFIG */
+	struct dma_slave_config dma_sconfig;
 };
 
 static inline struct dw_dma_chan_regs __iomem *