spi: use dev_get_platdata()

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi-ath79.c b/drivers/spi/spi-ath79.c
index 0e06407..37bad95 100644
--- a/drivers/spi/spi-ath79.c
+++ b/drivers/spi/spi-ath79.c
@@ -221,7 +221,7 @@
 	sp = spi_master_get_devdata(master);
 	platform_set_drvdata(pdev, sp);
 
-	pdata = pdev->dev.platform_data;
+	pdata = dev_get_platdata(&pdev->dev);
 
 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
 	master->setup = ath79_spi_setup;