Merge branch 'feature-21-TM7' of https://gitlab.eurecom.fr/oai/openairinterface5g into feature-21-TM7

reduced the max number of antenna ports to 6 to save memory (we are not using antenna port >5 anyway)
mult_cpx_conj_vector can now also do multiply add
beam_precoding now uses mult_cpx_conj_vector

Conflicts:
	targets/RT/USER/lte-enb.c

Develop integration w50

See merge request !61

We have a crash:

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fff7387d700 (LWP 1944)]
ulsch_decoding (eNB=eNB@entry=0x7fffaf73b010, proc=proc@entry=0x7fffaf73b480,
    UE_id=UE_id@entry=0 '\000',
    control_only_flag=control_only_flag@entry=0 '\000',
    Nbundled=<optimised out>, llr8_flag=<optimised out>)
    at /roux/merge/openairinterface5g/openair1/PHY/LTE_TRANSPORT/ulsch_decoding.c:1450
1450          *((__m256i *)&ulsch_harq->e[iprime]) = *((__m256i *)&y[j2]);

This commit reduces the apparition of the crash, but does not
eliminate it completely.

To be fixed after integration.

Merge branch '147-phy-test-mode-error-msg-dl-received-harqretx-round-1' of https://gitlab.eurecom.fr/oai/openairinterface5g into develop_integration_w50
correct issue 147 : --phy-test mode : error msg " DL Received HarqReTx round=1 m

Merge branch '147-phy-test-mode-error-msg-dl-received-harqretx-round-1' of https://gitlab.eurecom.fr/oai/openairinterface5g into 147-phy-test-mode-error-msg-dl-received-harqretx-round-1

correct issue 147 : --phy-test mode : error msg " DL Received HarqReTx round=1 mcs=28 rballoc=8191 rv=0 "

Problem in DCI NDI : the implementation use 5 HARQ processes, but process 0 N…

Merge branch '146-phy-test-mode-udate-fill_dci' of https://gitlab.eurecom.fr/oai/openairinterface5g into 146-phy-test-mode-udate-fill_dci

 - Problem in DCI NDI : the implementation use 5 HARQ processes, but process 0 NDI never toggled because it was reused on subframe 5 that is not carrying format 1 DCI. Fix -> use 8 harq processes instead of 5.
 - SI scheduled on every subframe 5 (even and odd frames) instead of only on even frames
 - Add DLSCH scheduling on subframe 5 for odd frames
 - change default rballoc from 0x7FFF to 0x1FFFF to support maximum 10MHz throughput

PDCP fix