Kirkwood: add Marvell Kirkwood gpio driver

Signed-off-by: Dieter Kiermaier <dk-arm-linux@gmx.de>
Acked-by: Prafulla Wadaskar <prafulla@marvell.com>
Tested-by: Heiko Schocher <hs@denx.de>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index f10144f..acba56c 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -25,6 +25,7 @@
 
 LIB 	:= $(obj)libgpio.a
 
+COBJS-$(CONFIG_KIRKWOOD_GPIO)	+= kw_gpio.o
 COBJS-$(CONFIG_MX31_GPIO)	+= mx31_gpio.o
 COBJS-$(CONFIG_PCA953X)		+= pca953x.o