gpio: Add APM X-Gene standby GPIO controller driver

Driver for standby GPIO controller of APM X-Gene SoCs on arm64.

Signed-off-by: Y Vo <yvo@apm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 81755f1..3031b19 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -105,6 +105,7 @@
 obj-$(CONFIG_GPIO_WM8350)	+= gpio-wm8350.o
 obj-$(CONFIG_GPIO_WM8994)	+= gpio-wm8994.o
 obj-$(CONFIG_GPIO_XGENE)	+= gpio-xgene.o
+obj-$(CONFIG_GPIO_XGENE_SB)	+= gpio-xgene-sb.o
 obj-$(CONFIG_GPIO_XILINX)	+= gpio-xilinx.o
 obj-$(CONFIG_GPIO_XTENSA)	+= gpio-xtensa.o
 obj-$(CONFIG_GPIO_ZEVIO)	+= gpio-zevio.o