Add --allintra to aomenc configuration

Allow the encoder to take --allintra configuration to work in all
intra mode. It behaves the same as the good quality usage as for
this commit.

BUG=aomedia:2959

Change-Id: I516f66470dd1bd0802b825cd2c8f2f7b512a3182
diff --git a/apps/aomenc.c b/apps/aomenc.c
index 4908058..78b1690 100644
--- a/apps/aomenc.c
+++ b/apps/aomenc.c
@@ -237,6 +237,7 @@
                                  &g_av1_codec_arg_defs.skip,
                                  &g_av1_codec_arg_defs.good_dl,
                                  &g_av1_codec_arg_defs.rt_dl,
+                                 &g_av1_codec_arg_defs.ai_dl,
                                  &g_av1_codec_arg_defs.quietarg,
                                  &g_av1_codec_arg_defs.verbosearg,
                                  &g_av1_codec_arg_defs.psnrarg,
@@ -593,6 +594,8 @@
       global->usage = AOM_USAGE_GOOD_QUALITY;  // Good quality usage
     } else if (arg_match(&arg, &g_av1_codec_arg_defs.rt_dl, argi)) {
       global->usage = AOM_USAGE_REALTIME;  // Real-time usage
+    } else if (arg_match(&arg, &g_av1_codec_arg_defs.ai_dl, argi)) {
+      global->usage = AOM_USAGE_ALL_INTRA;  // All intra usage
     } else if (arg_match(&arg, &g_av1_codec_arg_defs.use_yv12, argi)) {
       global->color_type = YV12;
     } else if (arg_match(&arg, &g_av1_codec_arg_defs.use_i420, argi)) {