blackfin: extgpio: 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.

Cc: Sonic Zhang <sonic.zhang@analog.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: adi-buildroot-devel@lists.sourceforge.net
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/blackfin/mach-bf538/ext-gpio.c

@@ -116,9 +116,9 @@ static struct gpio_chip bf538_porte_chip = {
 
 static int __init bf538_extgpio_setup(void)
 {
-	return gpiochip_add(&bf538_portc_chip) |
-		gpiochip_add(&bf538_portd_chip) |
-		gpiochip_add(&bf538_porte_chip);
+	return gpiochip_add_data(&bf538_portc_chip, NULL) |
+		gpiochip_add_data(&bf538_portd_chip, NULL) |
+		gpiochip_add_data(&bf538_porte_chip, NULL);
 }
 arch_initcall(bf538_extgpio_setup);