mfd: Add support for the RDC321x southbridge

This patch adds a new MFD driver for the RDC321x southbridge. This southbridge
is always present in the RDC321x System-on-a-Chip and provides access to some
GPIOs as well as a watchdog. Access to these two functions is done using the
southbridge PCI device configuration space.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 3c6a986..93d0e31 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -409,6 +409,15 @@
 	  LPC bridge function of the Intel SCH provides support for
 	  System Management Bus and General Purpose I/O.
 
+config MFD_RDC321X
+	tristate "Support for RDC-R321x southbridge"
+	select MFD_CORE
+	depends on PCI
+	help
+	  Say yes here if you want to have support for the RDC R-321x SoC
+	  southbridge which provides access to GPIOs and Watchdog using the
+	  southbridge PCI device configuration space.
+
 endmenu
 
 menu "Multimedia Capabilities Port drivers"