Misc fixes for 32x64 and 64x32 transforms

Change-Id: Ic843e99bd9b79cb9a0a26b95e3a48717ff2ec2a5
diff --git a/av1/common/av1_txfm.h b/av1/common/av1_txfm.h
index a61e25d..4c0a2d1 100644
--- a/av1/common/av1_txfm.h
+++ b/av1/common/av1_txfm.h
@@ -134,6 +134,7 @@
   TXFM_TYPE_IDENTITY8,
   TXFM_TYPE_IDENTITY16,
   TXFM_TYPE_IDENTITY32,
+  TXFM_TYPE_IDENTITY64,
 } TXFM_TYPE;
 
 typedef struct TXFM_1D_CFG {