gpio: add a driver for GPIO pins found on AMD-8111 south bridge chips

Add a driver to use GPIO pins available on several AMD south bridges
(currently only AMD 8111 is supported).

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index c4067d0..c2dfa9f 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -466,6 +466,18 @@
 
 	  If unsure, say N.
 
+config GPIO_AMD8111
+	tristate "AMD 8111 GPIO driver"
+	depends on PCI
+	help
+	  The AMD 8111 south bridge contains 32 GPIO pins which can be used.
+
+	  Note, that usually system firmware/ACPI handles GPIO pins on their
+	  own and users might easily break their systems with uncarefull usage
+	  of this driver!
+
+	  If unsure, say N
+
 config GPIO_LANGWELL
 	bool "Intel Langwell/Penwell GPIO support"
 	depends on PCI && X86