srsenb: remove QAM256 related options in RRC Connection Reconfig

this part of the RRC connection reconfig has caused issue for some
newer phones like the Iphone X, One Plus 6T.
The phone would receive the message but not respond with a reconfig
complete.

The patch fixes this issue by disabling QAM-256 support altogether.

srsenb/src/stack/rrc/rrc.cc

@@ -1798,15 +1798,6 @@ void rrc::ue::send_connection_reconf(srslte::unique_byte_buffer_t pdu)
   phy_cfg->pdsch_cfg_ded_present = true;
   phy_cfg->pdsch_cfg_ded.p_a     = parent->cfg.pdsch_cfg;
 
-  // Configure 256QAM
-  if (ue_capabilities.category_dl >= 11 && ue_capabilities.support_dl_256qam) {
-    phy_cfg->cqi_report_cfg_pcell_v1250.set_present(true);
-    cqi_report_cfg_v1250_s* cqi_report_cfg    = conn_reconf->rr_cfg_ded.phys_cfg_ded.cqi_report_cfg_pcell_v1250.get();
-    cqi_report_cfg->alt_cqi_table_r12_present = true;
-    cqi_report_cfg->alt_cqi_table_r12         = asn1::rrc::cqi_report_cfg_v1250_s::alt_cqi_table_r12_e_::all_sfs;
-    current_sched_ue_cfg.use_tbs_index_alt    = true;
-  }
-
   // Add SCells
   if (fill_scell_to_addmod_list(conn_reconf) != SRSLTE_SUCCESS) {
     parent->rrc_log->warning("Could not create configuration for Scell\n");
@@ -2003,14 +1994,6 @@ int rrc::ue::fill_scell_to_addmod_list(asn1::rrc::rrc_conn_recfg_r8_ies_s* conn_
     ul_cfg_ded.cqi_report_cfg_scell_r10.nom_pdsch_rs_epre_offset_r10          = 0;
     ul_cfg_ded.cqi_report_cfg_scell_r10.cqi_report_periodic_scell_r10_present = true;
 
-    // Add 256QAM
-    if (ue_capabilities.category_dl >= 11 && ue_capabilities.support_dl_256qam) {
-      cell.rr_cfg_ded_scell_r10.phys_cfg_ded_scell_r10.cqi_report_cfg_scell_v1250.set_present(true);
-      auto cqi_report_cfg_scell = cell.rr_cfg_ded_scell_r10.phys_cfg_ded_scell_r10.cqi_report_cfg_scell_v1250.get();
-      cqi_report_cfg_scell->alt_cqi_table_r12_present = true;
-      cqi_report_cfg_scell->alt_cqi_table_r12 = asn1::rrc::cqi_report_cfg_v1250_s::alt_cqi_table_r12_e_::all_sfs;
-    }
-
     // Get CQI allocation for secondary cell
     auto& cqi_setup = ul_cfg_ded.cqi_report_cfg_scell_r10.cqi_report_periodic_scell_r10.set_setup();
     get_cqi(&cqi_setup.cqi_pmi_cfg_idx, &cqi_setup.cqi_pucch_res_idx_r10, scell_idx);