Force EC_MULTISYMBOL on when --enable-cfl.

The cfl experiment depends on ec_multisymbol.

Change-Id: Ibbdf810b6c586f81fb8bcefa39696c7033970c47

av1/decoder/decodemv.c

@@ -1134,7 +1134,7 @@ static void read_intra_frame_mode_info(AV1_COMMON *const cm,
       mbmi->cfl_alpha_ind = read_cfl_alphas(
 #if CONFIG_EC_ADAPT
           xd->tile_ctx,
-#elif CONFIG_EC_MULTISYMBOL
+#else
           cm->fc,
 #endif  // CONFIG_EC_ADAPT
           r, mbmi->skip, mbmi->cfl_alpha_signs);

configure

@@ -518,6 +518,7 @@ post_process_cmdline() {
 
     # Fix up experiment dependencies
     enabled pvq && enable_feature ec_adapt
+    enabled cfl && enable_feature ec_multisymbol
     enabled ec_adapt && enable_feature ec_multisymbol
     enabled new_tokenset && enable_feature ec_multisymbol
     enabled new_multisymbol && enable_feature ec_multisymbol