Fix the bug that PVQ commit broke dering

Since PVQ's max block size equals to the max transform size,
daala's definition of OD_BSIZE_MAX was changed from 5 down to 4 to
use AV1's max trasform size 32x32. However, dering also uses
OD_BSIZE_MAX and assumes its value is 5, which caused dering
not working.

Change-Id: I9d82bb24adc7d57552a8e0a8a7e798e77d96fd4b
diff --git a/av1/common/blockd.h b/av1/common/blockd.h
index 1af3760..956c6c5 100644
--- a/av1/common/blockd.h
+++ b/av1/common/blockd.h
@@ -64,7 +64,7 @@
   int max_theta[PVQ_MAX_PARTITIONS];
   int qg[PVQ_MAX_PARTITIONS];
   int k[PVQ_MAX_PARTITIONS];
-  od_coeff y[OD_BSIZE_MAX * OD_BSIZE_MAX];
+  od_coeff y[OD_TXSIZE_MAX * OD_TXSIZE_MAX];
   int nb_bands;
   int off[PVQ_MAX_PARTITIONS];
   int size[PVQ_MAX_PARTITIONS];