mfd: stmpe: Use spi_get_drvdata()

Use the wrapper functions for getting and setting the driver data using
spi_device instead of using dev_{get|set}_drvdata with &spi->dev, so we
can directly pass a struct spi_device.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/stmpe-spi.c

@@ -103,7 +103,7 @@ stmpe_spi_probe(struct spi_device *spi)
 
 static int stmpe_spi_remove(struct spi_device *spi)
 {
-	struct stmpe *stmpe = dev_get_drvdata(&spi->dev);
+	struct stmpe *stmpe = spi_get_drvdata(spi);
 
 	return stmpe_remove(stmpe);
 }