arm: plat-orion: use GPIO driver on CONFIG_GPIOLIB

The GPIO driver uses gpiolib, thus it should be compiled when
CONFIG_GPIOLIB is defined and not only CONFIG_GENERIC_GPIO

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/plat-orion/Makefile

@@ -5,6 +5,6 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include
 
 obj-y                             += addr-map.o
 
-orion-gpio-$(CONFIG_GENERIC_GPIO) += gpio.o
+orion-gpio-$(CONFIG_GPIOLIB)      += gpio.o
 obj-$(CONFIG_PLAT_ORION_LEGACY)   += irq.o pcie.o time.o common.o mpp.o
 obj-$(CONFIG_PLAT_ORION_LEGACY)   += $(orion-gpio-y)