emev2: GPIOLIB: Enable support for OF

EMEV2 is now a DT platform, however the GPIO driver cannot be used
from a DT file since it does not fill out the of_node field in its
gpio_chip structure.

Signed-off-by: Ian Molton <ian.molton@codethink.co.uk>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b6ed304..a6d67c5 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -129,7 +129,7 @@
 
 config GPIO_EM
 	tristate "Emma Mobile GPIO"
-	depends on ARM
+	depends on ARM && OF_GPIO
 	help
 	  Say yes here to support GPIO on Renesas Emma Mobile SoCs.