pinctrl: introduce driver for Atmel PIO4 controller

Add a pinctrl/gpio driver for Atmel PIO4 controller available on SAMA5D2
chip family.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index cad077c..8bed0c2 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -12,6 +12,7 @@
 obj-$(CONFIG_PINCTRL_BF54x)	+= pinctrl-adi2-bf54x.o
 obj-$(CONFIG_PINCTRL_BF60x)	+= pinctrl-adi2-bf60x.o
 obj-$(CONFIG_PINCTRL_AT91)	+= pinctrl-at91.o
+obj-$(CONFIG_PINCTRL_AT91PIO4)	+= pinctrl-at91-pio4.o
 obj-$(CONFIG_PINCTRL_AMD)	+= pinctrl-amd.o
 obj-$(CONFIG_PINCTRL_DIGICOLOR)	+= pinctrl-digicolor.o
 obj-$(CONFIG_PINCTRL_FALCON)	+= pinctrl-falcon.o