rockchip: rk3188: Add pinctrl driver

Add a driver which supports pin multiplexing setup for the most commonly
used peripherals.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 0c832e1..397fbe1 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -132,6 +132,15 @@
 	  definitions and pin control functions for each available multiplex
 	  function.
 
+config ROCKCHIP_RK3188_PINCTRL
+	bool "Rockchip pin control driver"
+	depends on DM
+	help
+	  Support pin multiplexing control on Rockchip rk3188 SoCs. The driver
+	  is controlled by a device tree node which contains both the GPIO
+	  definitions and pin control functions for each available multiplex
+	  function.
+
 config ROCKCHIP_RK3288_PINCTRL
 	bool "Rockchip pin control driver"
 	depends on DM