ASoC: davinci-mcasp: Use a copy of pdata per instance during DT boot

Instead of modifying the static pdata struct per McASP instance we need to
allocate pdata for each McASP.
This way we can avoid configuration leakage from prior McASP to McASP
drivers probed at later time.
Reported-by: Misael Lopez Cruz <misael.lopez@ti.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/davinci/davinci-mcasp.c

@@ -1599,7 +1599,14 @@ static struct davinci_mcasp_pdata *davinci_mcasp_set_pdata_from_of(
 		pdata = pdev->dev.platform_data;
 		return pdata;
 	} else if (match) {
-		pdata = (struct davinci_mcasp_pdata*) match->data;
+		pdata = devm_kmemdup(&pdev->dev, match->data, sizeof(*pdata),
+				     GFP_KERNEL);
+		if (!pdata) {
+			dev_err(&pdev->dev,
+				"Failed to allocate memory for pdata\n");
+			ret = -ENOMEM;
+			return pdata;
+		}
 	} else {
 		/* control shouldn't reach here. something is wrong */
 		ret = -EINVAL;