- Hardcoding the freq_index when filling RACH
- Not handling DCI unless dci_rel_15 global is allocated
- Verifies ra_rnti matches in prach pdu and RACH
- Updates handling of DCI and RX from dl and tx reqs

Also, changed freq_index hardcode to 0.
Logging ra_rnti in gNB and NR UE

Need to figure out where to set ra_rnti in the NRUE.

Changed NFAPI_mode check in the gNB scheduler
to ensure that the frame is correctly updated for
msg3. Also added comments in NR UE for handling
the RAR and implementing the dci/rx_ind handover
for the RAR procedure.

The fix added in this commit may not be correct and
should be reviewed by Eurecom. For now we set the
future frame based on the PRACH recevied frame + 1.
Also fixed the copying of RACH ind into UL_INFO global.
RAR is being passed to NR UE.

Also fixed a few bugs in nr-nFAPI:
- Push16->push8 fix in packing of RACH
- Allocating memory for pdu_list and preamble_list in unpack
- Properly indexing through both lists during unpack
- Created new nr_rach handling function

Also fixed unpacking ul_tti_inds.

Several other changes in this commit include:
- Setting the number of PDUS in the ul_config
  to be zero when we will it (inside of the
  get_ul_config() function.)
- We reset the nprach flag to 0 for each slot.
- We return out of the prach scheduler if
  mac->ul_config == NULL
- Added error checking for array indexing
- Created a dummy scheduler response function.
- Allocated ul_config_req initially

Also calling the new L1_nsa_prach_procedures()
function after using the nr_ue_scheduler. Added
some error checking in the nr_ue_scheduler. Added
some error checking in the process_nsa_msg in both
the NR and LTE UE

Seems to be working at the moment but
may need to add more info in the rach_ind.
Also, need to verify gNB is getting the
rach_ind and starting RA procedure.

Had to hack the code to schedule the prach.
Need to verify this is ok because ul_config = NULL.
Also had to change logic for calling fill_schedule_response.

However, we are not properly calling the
nr_ue_get_rach() function. The RA is being
properly initialized. In the nr_ue_get_rach()
the pRACH is not scheduled. Tried to add in
the scheduling of this, but it crashes here.
The other changes include revering the
nr_ue_get_rach() changes from previous commit.
Also, changed a few log levels and reverted
a previous change in the NR UE RRC layer that
was incorrect.

Several places where memory ownership was changed
and the original owner was not set to NULL. Also,
the transaction_identifier is now based on the
received dl_dcch_msg in the LTE UE. Still need to
fix the t_id for the NR UE. Also added comments for
RACH procedure in NR UE.

At the moment, the NSA mode worked once, but shows
unpredictable behavior. Other times it does not work.
In this commit I added several LOG_A messages for NSA
mode. Also removed old comments that were added during
development. Lastly, more comments for all the hacks
have been added.

The eNB may only check for RRC_Complete in EPC
mode. Need to look at this further. Updated how
we pass the RRC_Complete msg from NR UE to LTE UE.
Need to still handle transaction_id from dl_dcch_msg
in the LTE UE and trans_id from nr_dl_msg.

It is seg faulting at the moment.

However, the NR UE is crashing because it is receiving
a second RRCReconfig message from the LTE UE and it is
having trouble decoding it. Need to understand this.

Also, updated the DCCH decode message to use
the sdu_size not RRC_BUF_SIZE. This was a bug fix.

Also removed several warnings by properly
declaring nr-nFAPI functions and removed
declaration of unused functions. Also, reverted
eNB configuration file changes.

nFAPI library update from IISc

See merge request aburger/openairinterface5g!40