Enable slots 3 & 4 in DL

Note: the slots to "enable" depend on the TDD configuration, so instead
of configuring it statically, we should read it from the configuration
file.

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c

@@ -360,7 +360,7 @@ void gNB_dlsch_ulsch_scheduler(module_id_t module_idP,
     nr_rrc_trigger(&ctxt, 0 /*CC_id*/, frame, slot >> *scc->ssbSubcarrierSpacing);
   }
 
-  const uint64_t dlsch_in_slot_bitmap = (1 << 1) | (1 << 2);
+  const uint64_t dlsch_in_slot_bitmap = (1 << 1) | (1 << 2) | (1 << 3) | (1 << 4);
   const uint64_t ulsch_in_slot_bitmap = (1 << 8);
 
   memset(RC.nrmac[module_idP]->cce_list[bwp_id][0],0,MAX_NUM_CCE*sizeof(int)); // coreset0