dmaengine/dma_slave: introduce inline wrappers

Add inline wrappers for device_prep_slave_sg() and device_prep_dma_cyclic()
interfaces to hide new parameter from current users of affected interfaces.
Convert current users to use new wrappers instead of direct calls.
Suggested by Russell King [https://lkml.org/lkml/2012/2/3/269].

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
diff --git a/arch/arm/plat-samsung/dma-ops.c b/arch/arm/plat-samsung/dma-ops.c
index 0747c77..a6ef396 100644
--- a/arch/arm/plat-samsung/dma-ops.c
+++ b/arch/arm/plat-samsung/dma-ops.c
@@ -79,11 +79,11 @@
 			    info->len, offset_in_page(info->buf));
 		sg_dma_address(&sg) = info->buf;
 
-		desc = chan->device->device_prep_slave_sg(chan,
+		desc = dmaengine_prep_slave_sg(chan,
 			&sg, 1, info->direction, DMA_PREP_INTERRUPT);
 		break;
 	case DMA_CYCLIC:
-		desc = chan->device->device_prep_dma_cyclic(chan,
+		desc = dmaengine_prep_dma_cyclic(chan,
 			info->buf, info->len, info->period, info->direction);
 		break;
 	default: