davinci: Correct return value of edma_alloc_channel api

Currently, edma_alloc_channel api is returning the channel
number without prepending the controller on which the
channel was allocated. So, if a channel is allocated on
2nd controller, calls subsequent to edma_alloc_channel would
never know that channel was allocated on the 2nd controller,
and continue to operate on 1st controller, resulting in edma
failure. This patch fixes this issue.

Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
diff --git a/arch/arm/mach-davinci/dma.c b/arch/arm/mach-davinci/dma.c
index 648fbb7..5a71f4d 100644
--- a/arch/arm/mach-davinci/dma.c
+++ b/arch/arm/mach-davinci/dma.c
@@ -642,7 +642,7 @@
 
 	map_dmach_queue(ctlr, channel, eventq_no);
 
-	return channel;
+	return EDMA_CTLR_CHAN(ctlr, channel);
 }
 EXPORT_SYMBOL(edma_alloc_channel);