pinctrl: uniphier: add UniPhier sLD3 pinctrl driver

Add pin-mux support for UniPhier sLD3 SoC.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/pinctrl/uniphier/Kconfig b/drivers/pinctrl/uniphier/Kconfig
index 7febea2..689e576 100644
--- a/drivers/pinctrl/uniphier/Kconfig
+++ b/drivers/pinctrl/uniphier/Kconfig
@@ -3,6 +3,12 @@
 config PINCTRL_UNIPHIER
 	bool
 
+config PINCTRL_UNIPHIER_SLD3
+	bool "UniPhier PH1-sLD3 SoC pinctrl driver"
+	depends on ARCH_UNIPHIER_SLD3
+	default y
+	select PINCTRL_UNIPHIER
+
 config PINCTRL_UNIPHIER_LD4
 	bool "UniPhier PH1-LD4 SoC pinctrl driver"
 	depends on ARCH_UNIPHIER_LD4