Bitmask: loop filtering using bitmask

Correctly build loop filter bitmask and apply filtering.
Do not support multi-thread loop filtering yet.

Change-Id: I6e3d4fce99d3ab5a702162df7dcd049a10edbc13
diff --git a/av1/encoder/encodetxb.c b/av1/encoder/encodetxb.c
index 124e00e..6c618a9 100644
--- a/av1/encoder/encodetxb.c
+++ b/av1/encoder/encodetxb.c
@@ -611,7 +611,8 @@
   const int num_planes = av1_num_planes(cm);
   int block[MAX_MB_PLANE] = { 0 };
   int row, col;
-  assert(bsize == get_plane_block_size(bsize, &xd->plane[0]));
+  assert(bsize == get_plane_block_size(bsize, xd->plane[0].subsampling_x,
+                                       xd->plane[0].subsampling_y));
   const int max_blocks_wide = max_block_wide(xd, bsize, 0);
   const int max_blocks_high = max_block_high(xd, bsize, 0);
   const BLOCK_SIZE max_unit_bsize = BLOCK_64X64;