gpio: adnp: Depend on OF_GPIO instead of OF

The driver accesses the of_node field of struct gpio_chip, which is only
available if OF_GPIO is selected. This solves a build issue on SPARC
which conflicts with OF_GPIO and therefore does not provide this field.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -466,7 +466,7 @@ config GPIO_ADP5588_IRQ
 
 config GPIO_ADNP
 	tristate "Avionic Design N-bit GPIO expander"
-	depends on I2C && OF
+	depends on I2C && OF_GPIO
 	help
 	  This option enables support for N GPIOs found on Avionic Design
 	  I2C GPIO expanders. The register space will be extended by powers