Mark rwmixcycle option as deprecated in the option parser

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/parse.h b/parse.h
index 42046b5..4e8124f 100644
--- a/parse.h
+++ b/parse.h
@@ -14,6 +14,7 @@
 	FIO_OPT_INT,
 	FIO_OPT_BOOL,
 	FIO_OPT_STR_SET,
+	FIO_OPT_DEPRECATED,
 };
 
 /*