[MFD] Add multimedia communication port core support

Add support for the core of the multimedia communication port
framework.  This is a port used to communicate with devices
with two DMA paths and a control path.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/Kconfig b/drivers/Kconfig
index cecab0a..46d655f 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -48,6 +48,8 @@
 
 source "drivers/misc/Kconfig"
 
+source "drivers/mfd/Kconfig"
+
 source "drivers/media/Kconfig"
 
 source "drivers/video/Kconfig"