dma: shdma: prepare for conversion to the shdma base library

By placing an anonymous union at the top of struct sh_dmae_slave we can
transparently prepare all device and client drivers for the upcoming
shdma-base conversion.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

include/linux/sh_dma.h

@@ -10,12 +10,16 @@
 #ifndef SH_DMA_H
 #define SH_DMA_H
 
-#include <linux/list.h>
 #include <linux/dmaengine.h>
+#include <linux/list.h>
+#include <linux/shdma-base.h>
 
 /* Used by slave DMA clients to request DMA to/from a specific peripheral */
 struct sh_dmae_slave {
+	union {
 		unsigned int		slave_id; /* Set by the platform */
+		struct shdma_slave	shdma_slave;
+	};
 	struct device			*dma_dev; /* Set by the platform */
 	const struct sh_dmae_slave_config	*config;  /* Set by the driver */
 };