Type-fix for inter_tx_size

inter_tx_size should be of type TX_SIZE, but it is listed as uint8_t.
Although this is currently fine (the UENUM1BYTE macro maps the enum
to uint8_t), it should really be TX_SIZE, so if the enum definition
ever changes, this data structure will be automatically updated.

Change-Id: I1426071224ae5cf7c8328fe172905c0179cc73de
diff --git a/av1/common/blockd.h b/av1/common/blockd.h
index bd586a4..1aae1f5 100644
--- a/av1/common/blockd.h
+++ b/av1/common/blockd.h
@@ -246,7 +246,7 @@
   MV_REFERENCE_FRAME ref_frame[2];
   FILTER_INTRA_MODE_INFO filter_intra_mode_info;
   int8_t skip_txfm;
-  uint8_t inter_tx_size[INTER_TX_SIZE_BUF_LEN];
+  TX_SIZE inter_tx_size[INTER_TX_SIZE_BUF_LEN];
   TX_SIZE tx_size;
   int8_t delta_lf_from_base;
   int8_t delta_lf[FRAME_LF_COUNT];