usb: gadget: ncm: convert to new function interface

Utilize our new configfs-based interface.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 127292f..bf7ad73 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -679,6 +679,7 @@
 	depends on NET
 	select USB_LIBCOMPOSITE
 	select USB_U_ETHER
+	select USB_F_NCM
 	select CRC32
 	help
 	  This driver implements USB CDC NCM subclass standard. NCM is