gpio: Loongson1: add Loongson1 GPIO driver

This patch adds GPIO driver for Loongson1B.

Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 08a93e0..37f0378 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -511,6 +511,13 @@
 	help
 	  Say yes here to support the GPIO device on ZTE ZX SoCs.
 
+config GPIO_LOONGSON1
+	tristate "Loongson1 GPIO support"
+	depends on MACH_LOONGSON32
+	select GPIO_GENERIC
+	help
+	  Say Y or M here to support GPIO on Loongson1 SoCs.
+
 endmenu
 
 menu "Port-mapped I/O GPIO drivers"