gpio: uniphier: add driver for UniPhier GPIO controller

This GPIO controller device is used on UniPhier SoCs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 845dc72..94fabb9 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -76,6 +76,12 @@
 	  of 'anonymous' GPIOs that do not belong to any device or bank.
 	  Select a suitable value depending on your needs.
 
+config GPIO_UNIPHIER
+	bool "UniPhier GPIO"
+	depends on ARCH_UNIPHIER
+	help
+	  Say yes here to support UniPhier GPIOs.
+
 config VYBRID_GPIO
 	bool "Vybrid GPIO driver"
 	depends on DM