dmaengine: OMAP: Register SDMA controller with Device Tree DMA driver

If the device-tree blob is present during boot, then register the SDMA
controller with the device-tree DMA driver so that we can use device-tree
to look-up DMA client information.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/arch/arm/mach-omap2/dma.c b/arch/arm/mach-omap2/dma.c
index dab9fc0..49fd0d5 100644
--- a/arch/arm/mach-omap2/dma.c
+++ b/arch/arm/mach-omap2/dma.c
@@ -28,6 +28,7 @@
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
+#include <linux/of.h>
 #include <linux/omap-dma.h>
 
 #include "soc.h"
@@ -304,6 +305,9 @@
 	if (res)
 		return res;
 
+	if (of_have_populated_dt())
+		return res;
+
 	pdev = platform_device_register_full(&omap_dma_dev_info);
 	if (IS_ERR(pdev))
 		return PTR_ERR(pdev);