gpio: zx: Add ZTE zx296702 GPIO support

Add ZTE zx296702 GPIO controller support

Signed-off-by: Jun Nie <jun.nie@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 4c9fa58..3a9dc1a 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1003,6 +1003,12 @@
 	  SPI driver for Freescale MC33880 high-side/low-side switch.
 	  This provides GPIO interface supporting inputs and outputs.
 
+config GPIO_ZX
+	bool "ZTE ZX GPIO support"
+	select GPIOLIB_IRQCHIP
+	help
+	  Say yes here to support the GPIO device on ZTE ZX SoCs.
+
 endmenu
 
 menu "USB GPIO expanders"