pinctrl: add pinctrl driver for imx6dl

The imx6dl is a derivative of imx6q with very limited difference.  These
two SoCs are so compatible that they can be handled as one platform in
software.  That said, we will not have target SOC_IMX6DL but just
reusing SOC_IMX6Q.   That's why the pinctrl-imx6dl driver is added here
with symbol PINCTRL_IMX6Q controlling the build of it.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 34f51d2..e8a564a 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -93,12 +93,12 @@
 	  Say Y here to enable the imx53 pinctrl driver
 
 config PINCTRL_IMX6Q
-	bool "IMX6Q pinctrl driver"
+	bool "IMX6Q/DL pinctrl driver"
 	depends on OF
 	depends on SOC_IMX6Q
 	select PINCTRL_IMX
 	help
-	  Say Y here to enable the imx6q pinctrl driver
+	  Say Y here to enable the imx6q/dl pinctrl driver
 
 config PINCTRL_LANTIQ
 	bool