ASoC: fsl_ssi: Save a dev reference for dev_err() purpose.

Most of functions only receive the ssi_private reference and don't have
a knowledge of 'dev' pointer, even for debug purpose.
Signed-off-by: NArnaud Mouiche <arnaud.mouiche@invoxia.com>
Tested-by: NCaleb Crome <caleb@crome.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

sound/soc/fsl/fsl_ssi.c

@@ -261,6 +261,7 @@ struct fsl_ssi_private {
 	struct fsl_ssi_dbg dbg_stats;
 
 	const struct fsl_ssi_soc_data *soc;
+	struct device *dev;
 };
 
 /*
@@ -1404,6 +1405,7 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 	}
 
 	ssi_private->soc = of_id->data;
+	ssi_private->dev = &pdev->dev;
 
 	sprop = of_get_property(np, "fsl,mode", NULL);
 	if (sprop) {