pinctrl: uniphier: add UniPhier pinctrl core support

The core support for the pinctrl drivers for all the UniPhier SoCs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pinctrl/uniphier/Kconfig b/drivers/pinctrl/uniphier/Kconfig
new file mode 100644
index 0000000..29a623d
--- /dev/null
+++ b/drivers/pinctrl/uniphier/Kconfig
@@ -0,0 +1,6 @@
+if ARCH_UNIPHIER
+
+config PINCTRL_UNIPHIER_CORE
+	bool
+
+endif