usb: gadget: add new usb gadget for ACM and mass storage

This driver provides two functions in one configuration:
a mass storage, and a ACM (serial port) link.
Heavily based on multi.c and cdc2.c

Signed-off-by: Klaus Schwarzkopf <schwarzkopf@sensortherm.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index a60b472..b21cd37 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -873,6 +873,16 @@
 	  It's only really useful for N900 hardware. If you're building
 	  a kernel for N900, say Y or M here. If unsure, say N.
 
+config USB_G_ACM_MS
+	tristate "CDC Composite Device (ACM and mass storage)"
+	depends on BLOCK
+	help
+	  This driver provides two functions in one configuration:
+	  a mass storage, and a CDC ACM (serial port) link.
+
+	  Say "y" to link the driver statically, or "m" to build a
+	  dynamically linked module called "g_acm_ms".
+
 config USB_G_MULTI
 	tristate "Multifunction Composite Gadget (EXPERIMENTAL)"
 	depends on BLOCK && NET