dmaengine: move drivers/of/dma.c -> drivers/dma/of-dma.c

as requested by Rob

Suggested-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 0b408bb..e92b5f0 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -325,6 +325,10 @@
 config DMA_VIRTUAL_CHANNELS
 	tristate
 
+config DMA_OF
+	def_bool y
+	depends on OF
+
 comment "DMA Clients"
 	depends on DMA_ENGINE