ARM mx3fb: check for DMA engine type

We have two dma engines in MX3 systems: The IPU and the SDMA
engine. We have to check if we got a channel from the correct
engine before proceeding with a channel.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
diff --git a/drivers/video/mx3fb.c b/drivers/video/mx3fb.c
index 7cfc170..ca0f6be 100644
--- a/drivers/video/mx3fb.c
+++ b/drivers/video/mx3fb.c
@@ -27,6 +27,7 @@
 #include <linux/clk.h>
 #include <linux/mutex.h>
 
+#include <mach/dma.h>
 #include <mach/hardware.h>
 #include <mach/ipu.h>
 #include <mach/mx3fb.h>
@@ -1420,6 +1421,9 @@
 	struct device *dev;
 	struct mx3fb_platform_data *mx3fb_pdata;
 
+	if (!imx_dma_is_ipu(chan))
+		return false;
+
 	if (!rq)
 		return false;