dfu:usb: DFU USB function (f_dfu) support for g_dnl composite gadget

Support for f_dfu USB function.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index 2c067c8..5bbdd36 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -30,6 +30,7 @@
 COBJS-y += epautoconf.o config.o usbstring.o
 COBJS-$(CONFIG_USB_GADGET_S3C_UDC_OTG) += s3c_udc_otg.o
 COBJS-$(CONFIG_USBDOWNLOAD_GADGET) += g_dnl.o
+COBJS-$(CONFIG_DFU_FUNCTION) += f_dfu.o
 endif
 ifdef CONFIG_USB_ETHER
 COBJS-y += ether.o epautoconf.o config.o usbstring.o