hotfix: fix TDD 20MHz DCI0 structure

In 20MHz the UE didn't do any uplink granted by DCI0.
It was replying to RAR, so uplink decoding was okay.

Turns out the DCI0 structure for TDD was wrong.

openair1/PHY/LTE_TRANSPORT/dci.h

@@ -230,7 +230,7 @@ typedef struct DCI1A_10MHz_TDD_1_6 DCI1A_10MHz_TDD_1_6_t;
 ///  DCI Format Type 0 (20 MHz,TDD1-6, 27 bits)
 struct DCI0_20MHz_TDD_1_6 {
   /// Padding
-  uint32_t padding:2;
+  uint32_t padding:3;
   /// CQI request
   uint32_t cqi_req:1;
   /// DAI