Set max layer depth for low delay settings

Properly set the max layer depth for the low delay settings.

Change-Id: I14777394f7a572dab7faee2ee6b5a746c626cf7e
diff --git a/av1/encoder/gop_structure.c b/av1/encoder/gop_structure.c
index 2e53c70..46d4845 100644
--- a/av1/encoder/gop_structure.c
+++ b/av1/encoder/gop_structure.c
@@ -858,6 +858,7 @@
     }
     gf_group->layer_depth[gf_index] = AOMMAX(log_gop_length - count, 0);
   }
+  gf_group->max_layer_depth = log_gop_length;
 }
 
 void av1_gop_setup_structure(AV1_COMP *cpi) {