Add end-to-end version of MFA FastSpeech2, test=tts

paddlespeech/t2s/exps/synthesize_e2e.py

@@ -246,9 +246,15 @@ def parse_args():
         type=str,
         help="text to synthesize, a 'utt_id sentence' pair per line.")
     parser.add_argument("--output_dir", type=str, help="output dir.")
-    parser.add_argument("--rhy_prediction_model", type=str, help="rhy prediction model path.")
-    parser.add_argument("--rhy_token", type=str, help="rhy prediction token path.")
-    parser.add_argument("--rhy_config", type=str, help="rhy prediction config path.")
+    parser.add_argument(
+        "--rhy_prediction_model",
+        type=str,
+        default="",
+        help="rhy prediction model path.")
+    parser.add_argument(
+        "--rhy_token", type=str, help="rhy prediction token path.")
+    parser.add_argument(
+        "--rhy_config", type=str, help="rhy prediction config path.")
 
     args = parser.parse_args()
     return args