pinctrl: Add bindings for ARTPEC-6 pinmux

Add the bindings for the pinmux functions in the
ARTPEC-6 SoC, including bias and drive strength.

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index 4eb32b3..ed5731a 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:	Documentation/devicetree/bindings/pinctrl/axis,artpec6-pinctrl.txt
 
 ARM/ASPEED MACHINE SUPPORT
 M:	Joel Stanley <joel@jms.id.au>