Cleanup dead func av1_get_tile_n_bits declaration

Change-Id: Ia672876bcd66eb87289e01646311567f8da02b87

av1/common/tile_common.h

diff --git a/av1/common/tile_common.h b/av1/common/tile_common.h
index 7f9544d..b7203ce 100644
--- a/av1/common/tile_common.h
+++ b/av1/common/tile_common.h
@@ -36,8 +36,6 @@
 
 void av1_tile_set_row(TileInfo *tile, const struct AV1Common *cm, int row);
 void av1_tile_set_col(TileInfo *tile, const struct AV1Common *cm, int col);
-void av1_get_tile_n_bits(int mi_cols, int *min_log2_tile_cols,
-                         int *max_log2_tile_cols);
 
 int av1_get_sb_rows_in_tile(struct AV1Common *cm, TileInfo tile);
 int av1_get_sb_cols_in_tile(struct AV1Common *cm, TileInfo tile);