rockchip: rk3288: Add pinctrl driver

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

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 35decf4..f537df4 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -1,4 +1,5 @@
 obj-y					+= pinctrl-uclass.o
 obj-$(CONFIG_$(SPL_)PINCTRL_GENERIC)	+= pinctrl-generic.o
 
+obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
 obj-$(CONFIG_PINCTRL_SANDBOX)	+= pinctrl-sandbox.o