pinctrl: add nexell driver

Changes in relation to FriendlyARM's U-Boot nanopi2-v2016.01:
- livetree API (dev_read_...) is used instead of fdt one (fdt...).
- doc/device-tree-bindings/pinctrl/nexell,s5pxx18-pinctrl.txt added.

Signed-off-by: Stefan Bosch <stefan_b@posteo.net>
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 4f662c4..92cff1b 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -21,6 +21,7 @@
 obj-$(CONFIG_PINCTRL_MTK)	+= mediatek/
 obj-$(CONFIG_PINCTRL_MSCC)	+= mscc/
 obj-$(CONFIG_ARCH_MVEBU)	+= mvebu/
+obj-$(CONFIG_ARCH_NEXELL)	+= nexell/
 obj-$(CONFIG_PINCTRL_SINGLE)	+= pinctrl-single.o
 obj-$(CONFIG_PINCTRL_STI)	+= pinctrl-sti.o
 obj-$(CONFIG_PINCTRL_STM32)	+= pinctrl_stm32.o