Add missing level 6.1

Missing from https://aomedia-review.googlesource.com/c/aom/+/82601

Change-Id: I77f90f511744c7400211c575ac652bcaaa2ca982
diff --git a/av1/encoder/encoder.c b/av1/encoder/encoder.c
index 5bf41f8..562ce0b 100644
--- a/av1/encoder/encoder.c
+++ b/av1/encoder/encoder.c
@@ -1178,6 +1178,7 @@
     level = SEQ_LEVEL_6_0;
   } else if (does_level_match(oxcf->width, oxcf->height, oxcf->init_framerate,
                               8192, 4352, 60.0, 2)) {
+    level = SEQ_LEVEL_6_1;
   } else if (does_level_match(oxcf->width, oxcf->height, oxcf->init_framerate,
                               8192, 4352, 120.0, 2)) {
     level = SEQ_LEVEL_6_2;