backlight: ili922x: use spi_set_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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/ili922x.c

@@ -488,7 +488,7 @@ static int ili922x_probe(struct spi_device *spi)
 	}
 
 	ili->spi = spi;
-	dev_set_drvdata(&spi->dev, ili);
+	spi_set_drvdata(spi, ili);
 
 	/* check if the device is connected */
 	ret = ili922x_read(spi, REG_DRIVER_CODE_READ, &reg);