pinctrl: mvebu: add pinctrl driver for Marvell Armada 39x

This commit adds a new pinctrl driver for the Marvell Armada 39x
family of processors, which hooks into the existing infrastructure to
support pin-muxing on Marvell EBU processors. Two variants of the
Armada 39x are supported: 88F6920 (Armada 390) and 88F6928 (Armada
398), which have a few differences in the available functions for
certain pins.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/mvebu/Kconfig b/drivers/pinctrl/mvebu/Kconfig
index d6dd835..1706024 100644
--- a/drivers/pinctrl/mvebu/Kconfig
+++ b/drivers/pinctrl/mvebu/Kconfig
@@ -26,6 +26,10 @@
 	bool
 	select PINCTRL_MVEBU
 
+config PINCTRL_ARMADA_39X
+	bool
+	select PINCTRL_MVEBU
+
 config PINCTRL_ARMADA_XP
 	bool
 	select PINCTRL_MVEBU