gpio: New driver for LSI ZEVIO SoCs

This driver supports the GPIO controller found in LSI ZEVIO SoCs.
It has been successfully tested on a TI nspire CX calculator.

Signed-off-by: Fabian Vogt <fabian@ritter-vogt.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 3bddd36..5e8bd21 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -145,6 +145,12 @@
 	depends on ARCH_EP93XX
 	select GPIO_GENERIC
 
+config GPIO_ZEVIO
+	bool "LSI ZEVIO SoC memory mapped GPIOs"
+	depends on OF
+	help
+	  Say yes here to support the GPIO controller in LSI ZEVIO SoCs.
+
 config GPIO_MM_LANTIQ
 	bool "Lantiq Memory mapped GPIOs"
 	depends on LANTIQ && SOC_XWAY