Make separate header for nr_pdcp instead of using 4G pdcp

Creates function that have nr_pdcp_ prepended to their name, and change
the signature of some functions for the 5G PDCP:

- nr_pdcp_layer_init()
- nr_pdcp_data_req()
- nr_pdcp_remove_UE()
- nr_pdcp_config_set_security()
- nr_pdcp_remove_UE()
- Make separate functions for nr_pdcp_data_req_srb/drb()

executables/nr-ue.c

@@ -33,7 +33,7 @@
 #include "executables/softmodem-common.h"
 #include "PHY/NR_REFSIG/refsig_defs_ue.h"
 #include "radio/COMMON/common_lib.h"
-#include "pdcp.h"
+#include "LAYER2/nr_pdcp/nr_pdcp_oai_api.h"
 
 /*
  *  NR SLOT PROCESSING SEQUENCE
@@ -359,7 +359,7 @@ static void *NRUE_phy_stub_standalone_pnf_task(void *arg)
       NR_UE_MAC_INST_t *mac = get_mac_inst(0);
       protocol_ctxt_t ctxt;
       PROTOCOL_CTXT_SET_BY_MODULE_ID(&ctxt, 0, ENB_FLAG_NO, mac->crnti, frame, slot, 0);
-      pdcp_run(&ctxt);
+      nr_pdcp_run(&ctxt);
     }
     process_queued_nr_nfapi_msgs(mac, sfn_slot);
   }
@@ -627,7 +627,7 @@ void UE_processing(nr_rxtx_thread_data_t *rxtxD) {
       NR_UE_MAC_INST_t *mac = get_mac_inst(0);
       protocol_ctxt_t ctxt;
       PROTOCOL_CTXT_SET_BY_MODULE_ID(&ctxt, UE->Mod_id, ENB_FLAG_NO, mac->crnti, proc->frame_rx, proc->nr_slot_rx, 0);
-      pdcp_run(&ctxt);
+      nr_pdcp_run(&ctxt);
     }
   }