Move some 2pass opts to generic rate control opts

Move bias-pct, minsection-pct and maxsection-pct options
in aomenc to generic rate control options group, since
the last two are used for both 1-pass and 2-pass and
the first one could be used for 1-pass as well (even
though it is not used currently).

Change-Id: I2b11888d74c81a7818f4b49deb02955825daab62
diff --git a/apps/aomenc.c b/apps/aomenc.c
index 432009f..7c06dfe 100644
--- a/apps/aomenc.c
+++ b/apps/aomenc.c
@@ -334,6 +334,12 @@
     ARG_DEF(NULL, "buf-initial-sz", 1, "Client initial buffer size (ms)");
 static const arg_def_t buf_optimal_sz =
     ARG_DEF(NULL, "buf-optimal-sz", 1, "Client optimal buffer size (ms)");
+static const arg_def_t bias_pct =
+    ARG_DEF(NULL, "bias-pct", 1, "CBR/VBR bias (0=CBR, 100=VBR)");
+static const arg_def_t minsection_pct =
+    ARG_DEF(NULL, "minsection-pct", 1, "GOP min bitrate (% of target)");
+static const arg_def_t maxsection_pct =
+    ARG_DEF(NULL, "maxsection-pct", 1, "GOP max bitrate (% of target)");
 static const arg_def_t *rc_args[] = { &dropframe_thresh,
                                       &resize_mode,
                                       &resize_denominator,
@@ -352,16 +358,11 @@
                                       &buf_sz,
                                       &buf_initial_sz,
                                       &buf_optimal_sz,
+                                      &bias_pct,
+                                      &minsection_pct,
+                                      &maxsection_pct,
                                       NULL };
 
-static const arg_def_t bias_pct =
-    ARG_DEF(NULL, "bias-pct", 1, "CBR/VBR bias (0=CBR, 100=VBR)");
-static const arg_def_t minsection_pct =
-    ARG_DEF(NULL, "minsection-pct", 1, "GOP min bitrate (% of target)");
-static const arg_def_t maxsection_pct =
-    ARG_DEF(NULL, "maxsection-pct", 1, "GOP max bitrate (% of target)");
-static const arg_def_t *rc_twopass_args[] = { &bias_pct, &minsection_pct,
-                                              &maxsection_pct, NULL };
 static const arg_def_t fwd_kf_enabled =
     ARG_DEF(NULL, "enable-fwd-kf", 1, "Enable forward reference keyframes");
 static const arg_def_t kf_min_dist =
@@ -1048,8 +1049,6 @@
   arg_show_usage(fout, global_args);
   fprintf(fout, "\nRate Control Options:\n");
   arg_show_usage(fout, rc_args);
-  fprintf(fout, "\nTwopass Rate Control Options:\n");
-  arg_show_usage(fout, rc_twopass_args);
   fprintf(fout, "\nKeyframe Placement Options:\n");
   arg_show_usage(fout, kf_args);
 #if CONFIG_AV1_ENCODER