gpio: driver for 42 AB8500 GPIO pins

To get rid of port expanders, the free GPIOs of ab8500
can be used. There are 42 GPIO pins. Out of which 16
are interrupt capable.This patch implements 16 virtual
IRQ mapped to 16 interrupt capable AB8500 GPIOs.

Signed-off-by: Bibek Basu <bibek.basu@stericsson.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
[Renamed header file as per MFD structure]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d8d0cda..d374320 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -414,4 +414,9 @@
 	  This driver provides support for driving the pins in output
 	  mode only. Input mode is not supported.
 
+config AB8500_GPIO
+	bool "ST-Ericsson AB8500 Mixed Signal Circuit gpio functions"
+	depends on AB8500_CORE
+	help
+	  Select this to enable the AB8500 IC GPIO driver
 endif