Revert "kssb < 16 or we cannot do reestablishment: add assert in DU"

This reverts commit eaf28414ca.

This assertion was introduced as we (wrongfully) thought we needed to
calculate the SSB ARFCN at the CU. Since PBCH might carry one bit, which
is not available at the CU, only certain SSB ARFCNs would have been
possible.

With the availability of the SSB ARFCN through the
MeasurementTimingConfiguration, this is not necessary anymore.

ci-scripts/conf_files/gnb.sa.band78.51prb.usrpb200.conf

@@ -30,7 +30,7 @@ gNBs =
       absoluteFrequencySSB                                             = 620736;
       dl_frequencyBand                                                 = 78;
       # this is 3300.30 MHz
-      dl_absoluteFrequencyPointA                                       = 620052;
+      dl_absoluteFrequencyPointA                                       = 620020;
       #scs-SpecificCarrierList
         dl_offstToCarrier                                              = 0;
 # subcarrierSpacing

openair2/LAYER2/NR_MAC_gNB/config.c

@@ -540,13 +540,6 @@ static void config_common(gNB_MAC_INST *nrmac, nr_pdsch_AntennaPorts_t pdsch_Ant
        get_ssb_subcarrier_offset(*scc->downlinkConfigCommon->frequencyInfoDL->absoluteFrequencySSB,
                                  scc->downlinkConfigCommon->frequencyInfoDL->absoluteFrequencyPointA,
                                  *scc->ssbSubcarrierSpacing);
-
-  AssertFatal(cfg->ssb_table.ssb_subcarrier_offset.value < 16,
-              "cannot handle ssb_subcarrier_offset %d resulting from Point A %ld SSB %ld: please increase dl_absoluteFrequencyPointA "
-              "in the config by 16\n",
-              cfg->ssb_table.ssb_subcarrier_offset.value,
-              scc->downlinkConfigCommon->frequencyInfoDL->absoluteFrequencyPointA,
-              *scc->downlinkConfigCommon->frequencyInfoDL->absoluteFrequencySSB);
   cfg->ssb_table.ssb_subcarrier_offset.tl.tag = NFAPI_NR_CONFIG_SSB_SUBCARRIER_OFFSET_TAG;
   cfg->num_tlv++;