pinctrl: Add one-register-per-pin type device tree based pinctrl driver

Add one-register-per-pin type device tree based pinctrl driver.

This driver has been tested on omap2+ series of processors,
where there is either an 8 or 16-bit padconf register for each pin.
Support for other similar pinmux controllers can be added.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 4c05fe8..54e3588 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -102,6 +102,14 @@
 	select PINCTRL_PXA3xx
 	select PINCONF
 
+config PINCTRL_SINGLE
+	tristate "One-register-per-pin type device tree based pinctrl driver"
+	depends on OF
+	select PINMUX
+	select PINCONF
+	help
+	  This selects the device tree based generic pinctrl driver.
+
 config PINCTRL_SIRF
 	bool "CSR SiRFprimaII pin controller driver"
 	depends on ARCH_PRIMA2