ARM: SAMSUNG: use static declaration when it is not used in other files

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/arch/arm/plat-samsung/dma-ops.c b/arch/arm/plat-samsung/dma-ops.c
index 0747c77..301d9c3 100644
--- a/arch/arm/plat-samsung/dma-ops.c
+++ b/arch/arm/plat-samsung/dma-ops.c
@@ -116,7 +116,7 @@
 	return dmaengine_terminate_all((struct dma_chan *)ch);
 }
 
-struct samsung_dma_ops dmadev_ops = {
+static struct samsung_dma_ops dmadev_ops = {
 	.request	= samsung_dmadev_request,
 	.release	= samsung_dmadev_release,
 	.prepare	= samsung_dmadev_prepare,