gpio: Fix dependency for gpio-delay

This driver relies on OF_GPIO features, add a dependency to Kconfig.

Fixes: cf5dec8 ("gpio: Add gpio delay driver")
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: tq-steina

drivers/gpio/Kconfig

@@ -1735,6 +1735,7 @@ config GPIO_AGGREGATOR
 
 config GPIO_DELAY
 	tristate "GPIO delay"
+	depends on OF_GPIO
 	help
 	  Say yes here to enable the GPIO delay, which provides a way to
 	  configure platform specific delays for GPIO ramp-up or ramp-down