- configure_fapi_dl_pdu is handling the nfapi_nr_dl_config_request_pdu
 - while configure_fapi_dl_Tx is now handling the nfapi_tx_request_pdu

this was necessary because the computation of the TBS size is needed in the phytest scheduler
before even knowing if there is any data to transmit. The tx_request_pdu must be handled instead
only when there is data to transmit.

Integration develop nr 2019w50

See merge request oai/openairinterface5g!735

Merge remote-tracking branch 'origin/ru-parallel-beamforming-merge' into integration-develop-nr-2019w50

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Initial implementation.

nr_rlc/nr_rlc_oai_api.c will need some clean rewrite at some point.

More testing is also needed.

bug fix: ue was not reading options + more debug printf cleanup in openair1/PHY/NR_UE_TRANSPORT/dci_nr.c

- merged nr-schedule_ue_spec into nr_schedule_uss_dlsch_phytest
- enabled nr_ue_send_sdu for S1 mode
- increased ta_timer to 100
- restored NR_UPLINK_SLOT to 2 (as it was in develop-nr)
- fixed logic for S1 and noS1 modes
- code cleanup and formatting

- the new option -k allows to skip the built of shared libraries, rfsimulator
  basicsimulator and transport protocol libraries
- default compilation remains untouched as is still building all libraries
- this option allows to save a massive amount of time when compiling
  repeatedly for debugging purposes

- introduced new parameter in nr_ue_dl_indication for UL time alignment
- moved TA timer logic one level up so that now is executed every slot
- set timer value to 80 slots to cope with the sl_ahead design
- introduced new TA-related members to gNB MAC instance struct

- UE processing capability 1
- Setting the TA update to be applied after the reception of the TA command
- Durations of N1 and N2 symbols corresponding to PDSCH and PUSCH are
  computed according to sections 5.3 and 6.4 of TS 38.214
- Introduced tables 5.3-1, 5.3-2, 6.4-1, 6.4-2 from TS 38.214

Maintenance of Uplink Time Alignment. Introduced control on TA transmission and TA update application.

- ta_timer at gNB side to control the transmission of TA to the UE. This is now happening every 20 slots.
- when the timer resets gNB is now transmitting the TA whether it is zero or not.
- introduced struct NR_UL_TIME_ALIGNMENT_t to handle configuration of time alignment related parameters.
- UE PHY RX: is now triggered through a flag when to store the TA command, the frame and slot
  when the application should occur.
- UE PHY TX: when the tx frame and slot match the time alignment configuration, it process the TA command and applies the
  TA update

Integration PHY and MAC procedures for Timing Advance updates. Compilation and run is OK. TA updates need further fixes as not working as expected.

- "nr_process_timing_advance": TA to be applied is commented out, need to be uncommented
- with introduced delay of 50 in rx_rf, TA update should be 34 in MAC CE
  but this does not occur when ta is applied at UE side according to standard
- introduced ULSCH scheduler and NR RX SDU functions
- fixes to logic in UL fill RX indication
- added crc indication in UL RX
- temporary hardcoded UE_id to 0, rnti not considered in the logic

- Initial gNB DLSCH and UE spec scheduling implentation
- MAC PDU generation (including header as per TS 38.321)
- MAC PDU processing at UE side with extracion of TA updates
- General code cleanup
- Introduced NR MAC COMMON folder, moved common files here

Fix usrp_lib for threequarter sampling

See merge request oai/openairinterface5g!732