usb: uvc: add missing MODULE_DESCRIPTION() macro

With ARCH=arm64, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/media/common/uvc.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

drivers/media/common/uvc.c

@@ -180,4 +180,5 @@ const struct uvc_format_desc *uvc_format_by_guid(const u8 guid[16])
 }
 EXPORT_SYMBOL_GPL(uvc_format_by_guid);
 
+MODULE_DESCRIPTION("USB Video Class common code");
 MODULE_LICENSE("GPL");