gpio: Add VIA VX855 GPIO driver

This is needed for supporting the upcoming VX855 camera and OLPC DCON
drivers, as well as the advanced viafb features on non-OLPC hardware
based on this chip.

Based on earlier work by Harald Welte.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index dd9b4ba..3143ac7 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -116,6 +116,18 @@
 	  This driver can also be built as a module. If so, the module
 	  will be called sch-gpio.
 
+config GPIO_VX855
+	tristate "VIA VX855/VX875 GPIO"
+	depends on GPIOLIB
+	select MFD_CORE
+	select MFD_VX855
+	help
+	  Support access to the VX855/VX875 GPIO lines through the gpio library.
+
+	  This driver provides common support for accessing the device,
+	  additional drivers must be enabled in order to use the
+	  functionality of the device.
+
 comment "I2C GPIO expanders:"
 
 config GPIO_MAX7300