Refactor (gNB Config): look up neighbour-list nr_cellid by name with gpd

Outer gNB neighbour_list entries now only declare the serving cell
nr_cellid. The code resolves that field with gpd instead of a fixed column
index.

Changes:
- gnb_paramdef.h: remove unused NEIGHBOUR_CELL_PHYSICAL_ID from
  GNB_NEIGHBOUR_LIST_PARAM_LIST (keep NRCELLID only).
- gnb_config.c: in fill_neighbour_cell_configuration, set nr_cell_id
  from gpd

openair2/GNB_APP/gnb_config.c

@@ -2086,7 +2086,8 @@ static void fill_neighbour_cell_configuration(const uint8_t gnb_idx, gNB_RRC_INS
   seq_arr_init(rrc->neighbour_cell_configuration, sizeof(neighbour_cell_configuration_t));
 
   for (int elm = 0; elm < nlist.numelt; ++elm) {
-    neighbour_cell_configuration_t cell = {.nr_cell_id = *nlist.paramarray[elm][0].u64ptr};
+    neighbour_cell_configuration_t cell = {0};
+    cell.nr_cell_id = *gpd(nlist.paramarray[elm], sizeofArray(nparams), GNB_CONFIG_STRING_NRCELLID)->u64ptr;
     snprintf(path, sizeof(path), "%s.[%i].%s.[%i]", GNB_CONFIG_STRING_GNB_LIST, gnb_idx, GNB_CONFIG_STRING_NEIGHBOUR_LIST, elm);
     GET_PARAMS_LIST(ncell_list, ncell_params, GNBNEIGHBOURCELLPARAMS_DESC, GNB_CONFIG_STRING_NEIGHBOUR_CELL_LIST, path);
     if (ncell_list.numelt < 1)

openair2/GNB_APP/gnb_paramdef.h

@@ -289,7 +289,6 @@ typedef enum {
 #define GNB_NEIGHBOUR_LIST_PARAM_LIST {                                                                  \
 /*   optname                                                  helpstr                                 paramflags                    XXXptr     def val          type    numelt */ \
   {GNB_CONFIG_STRING_NRCELLID,                              "cell nrCell Id which has neighbours",              PARAMFLAG_MANDATORY,           .u64ptr=NULL, .defint64val=0,               TYPE_UINT64,    0},    \
-  {GNB_CONFIG_STRING_NEIGHBOUR_CELL_PHYSICAL_ID,            "neighbour cell physical id",            PARAMFLAG_MANDATORY,           .uptr=NULL,   .defuintval=0,                TYPE_UINT,      0},    \
 }
 // clang-format on
 #define GNB_CONFIG_STRING_NEIGHBOUR_CELL_LIST "neighbour_cell_configuration"