dmaengine: shdma: Common SH_DMA_SLAVE_NUMBER

Move SHDMA_SLAVE_NUMBER from asm/dmaengine.h to
shdma.h. Set it to 256 to support a wide range
of processors. The amount of memory consumed by
this change is limited to 256 bits.

While at it, rename to SH_DMA_SLAVE_NUMBER to
match with the rest of the file.

Signed-off-by: Magnus Damm <damm@opensource.se>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/drivers/dma/shdma.c b/drivers/dma/shdma.c
index e5588f4..8360538 100644
--- a/drivers/dma/shdma.c
+++ b/drivers/dma/shdma.c
@@ -44,7 +44,7 @@
 #define LOG2_DEFAULT_XFER_SIZE	2
 
 /* A bitmask with bits enough for enum sh_dmae_slave_chan_id */
-static unsigned long sh_dmae_slave_used[BITS_TO_LONGS(SHDMA_SLAVE_NUMBER)];
+static unsigned long sh_dmae_slave_used[BITS_TO_LONGS(SH_DMA_SLAVE_NUMBER)];
 
 static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all);
 
@@ -274,7 +274,7 @@
 	struct sh_dmae_pdata *pdata = shdev->pdata;
 	int i;
 
-	if (param->slave_id >= SHDMA_SLAVE_NUMBER)
+	if (param->slave_id >= SH_DMA_SLAVE_NUMBER)
 		return NULL;
 
 	for (i = 0; i < pdata->slave_num; i++)