ASoC: fsl_rpmsg: Check -EPROBE_DEFER for getting clocks

The devm_clk_get() may return -EPROBE_DEFER, then clocks
will be assigned to NULL wrongly. As the clocks are
optional so we can use devm_clk_get_optional() instead of
devm_clk_get().

Fixes: b73d9e6225 ("ASoC: fsl_rpmsg: Add CPU DAI driver for audio base on rpmsg")
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1629266614-6942-1-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/fsl_rpmsg.c

@@ -165,25 +165,25 @@ static int fsl_rpmsg_probe(struct platform_device *pdev)
 	}
 
 	/* Get the optional clocks */
-	rpmsg->ipg = devm_clk_get(&pdev->dev, "ipg");
+	rpmsg->ipg = devm_clk_get_optional(&pdev->dev, "ipg");
 	if (IS_ERR(rpmsg->ipg))
-		rpmsg->ipg = NULL;
+		return PTR_ERR(rpmsg->ipg);
 
-	rpmsg->mclk = devm_clk_get(&pdev->dev, "mclk");
+	rpmsg->mclk = devm_clk_get_optional(&pdev->dev, "mclk");
 	if (IS_ERR(rpmsg->mclk))
-		rpmsg->mclk = NULL;
+		return PTR_ERR(rpmsg->mclk);
 
-	rpmsg->dma = devm_clk_get(&pdev->dev, "dma");
+	rpmsg->dma = devm_clk_get_optional(&pdev->dev, "dma");
 	if (IS_ERR(rpmsg->dma))
-		rpmsg->dma = NULL;
+		return PTR_ERR(rpmsg->dma);
 
-	rpmsg->pll8k = devm_clk_get(&pdev->dev, "pll8k");
+	rpmsg->pll8k = devm_clk_get_optional(&pdev->dev, "pll8k");
 	if (IS_ERR(rpmsg->pll8k))
-		rpmsg->pll8k = NULL;
+		return PTR_ERR(rpmsg->pll8k);
 
-	rpmsg->pll11k = devm_clk_get(&pdev->dev, "pll11k");
+	rpmsg->pll11k = devm_clk_get_optional(&pdev->dev, "pll11k");
 	if (IS_ERR(rpmsg->pll11k))
-		rpmsg->pll11k = NULL;
+		return PTR_ERR(rpmsg->pll11k);
 
 	platform_set_drvdata(pdev, rpmsg);
 	pm_runtime_enable(&pdev->dev);