pinctrl: Add pincontrol driver for ARTPEC-6 SoC

Add pinctrl driver support for the Axis ARTPEC-6 SoC.
There are only some pins that actually have different
functions available, but all can control bias (pull-up/-down)
and drive strength.

Code originally written by Chris Paterson.

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index ed5731a..1d5bc97 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1088,6 +1088,7 @@
 F:	arch/arm/mach-artpec
 F:	arch/arm/boot/dts/artpec6*
 F:	drivers/clk/axis
+F:	drivers/pinctrl/pinctrl-artpec*
 F:	Documentation/devicetree/bindings/pinctrl/axis,artpec6-pinctrl.txt
 
 ARM/ASPEED MACHINE SUPPORT