gpio: Driver for SYSCON-based GPIOs

SYSCON driver was designed for using memory areas (registers)
that are used in several subsystems. There are systems (CPUs)
which use bits in one register for various purposes and thus
should be handled by various kernel subsystems. This driver
allows you to use the individual SYSCON bits as GPIOs.
ARM CLPS711X SYSFLG1 input lines has been added as first user
of this driver.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -290,6 +290,12 @@ config GPIO_STA2X11
 	  Say yes here to support the STA2x11/ConneXt GPIO device.
 	  The GPIO module has 128 GPIO pins with alternate functions.
 
+config GPIO_SYSCON
+	tristate "GPIO based on SYSCON"
+	depends on MFD_SYSCON && OF
+	help
+	  Say yes here to support GPIO functionality though SYSCON driver.
+
 config GPIO_TS5500
 	tristate "TS-5500 DIO blocks and compatibles"
 	depends on TS5500 || COMPILE_TEST