pinctrl: uniphier: add UniPhier ProXstream2 pinctrl driver

Add pin configuration and pinmux support for UniPhier ProXstream2
SoC.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/pinctrl/uniphier/Kconfig b/drivers/pinctrl/uniphier/Kconfig
index 9d3065d..7f729b6 100644
--- a/drivers/pinctrl/uniphier/Kconfig
+++ b/drivers/pinctrl/uniphier/Kconfig
@@ -27,4 +27,10 @@
 	default y
 	select PINCTRL_UNIPHIER_CORE
 
+config PINCTRL_UNIPHIER_PROXSTREAM2
+	bool "UniPhier ProXstream2 SoC pinctrl driver"
+	depends on MACH_PROXSTREAM2
+	default y
+	select PINCTRL_UNIPHIER_CORE
+
 endif