usb: gadget: Make webcam gadget select USB_LIBCOMPOSITE

Composite gadget support is now available as a library instead of being
built with each gadget. Composite drivers need to select
USB_LIBCOMPOSITE.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index dfb51a4..e0ff51b 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -952,6 +952,7 @@
 config USB_G_WEBCAM
 	tristate "USB Webcam Gadget"
 	depends on VIDEO_DEV
+	select USB_LIBCOMPOSITE
 	help
 	  The Webcam Gadget acts as a composite USB Audio and Video Class
 	  device. It provides a userspace API to process UVC control requests