mfd: vexpress-sysreg: Switch to gpiochip_add_data()

We're planning to remove the gpiochip_add() function to swith
to gpiochip_add_data() with NULL for data argument.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/vexpress-sysreg.c b/drivers/mfd/vexpress-sysreg.c
index 855c020..201a3ea2 100644
--- a/drivers/mfd/vexpress-sysreg.c
+++ b/drivers/mfd/vexpress-sysreg.c
@@ -202,7 +202,7 @@
 	bgpio_init(mmc_gpio_chip, &pdev->dev, 0x4, base + SYS_MCI,
 			NULL, NULL, NULL, NULL, 0);
 	mmc_gpio_chip->ngpio = 2;
-	gpiochip_add(mmc_gpio_chip);
+	gpiochip_add_data(mmc_gpio_chip, NULL);
 
 	return mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO,
 			vexpress_sysreg_cells,