dmaengine: stm32-dma: use reset controller only at probe time

Remove reset controller reference from device instance since it is
used only at probe time.
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-3-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/stm32-dma.c

@@ -207,7 +207,6 @@ struct stm32_dma_device {
 	struct dma_device ddev;
 	void __iomem *base;
 	struct clk *clk;
-	struct reset_control *rst;
 	bool mem2mem;
 	struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS];
 };
@@ -1275,6 +1274,7 @@ static int stm32_dma_probe(struct platform_device *pdev)
 	struct dma_device *dd;
 	const struct of_device_id *match;
 	struct resource *res;
+	struct reset_control *rst;
 	int i, ret;
 
 	match = of_match_device(stm32_dma_of_match, &pdev->dev);
@@ -1309,11 +1309,11 @@ static int stm32_dma_probe(struct platform_device *pdev)
 	dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
 						"st,mem2mem");
 
-	dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
-	if (!IS_ERR(dmadev->rst)) {
-		reset_control_assert(dmadev->rst);
+	rst = devm_reset_control_get(&pdev->dev, NULL);
+	if (!IS_ERR(rst)) {
+		reset_control_assert(rst);
 		udelay(2);
-		reset_control_deassert(dmadev->rst);
+		reset_control_deassert(rst);
 	}
 
 	dma_cap_set(DMA_SLAVE, dd->cap_mask);