bugfix for DCCH2/SRB2 in eNB_scheduler_dlsch.c, demultiplexing SIMD alignment issue in ulsch_decoding.c, IF5 fronthaul modification in lte-enb.c

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.

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 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

enhanced wireshark logging. also logs BCH, PRACH and RAR. Tested with wireshark 2.2.2 on linux and windows

see issue #45

This reverts commit 5466562b16d70f2729f6103e1c0d3ee619470191.

fixed missing a slot_fep() processing on the 1st OFDM symbol of the first DL subframe after UL, causing no SI-RNTI DCI detected

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

added prach buffer for if4p5 processing in RRU. This fixed a critical bug which was seen for bandwidths greater than 5 MHz.  RRU tested with 5/10 MHz on 1.5 GHz Atom.

 - 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

- add mcs to ENB_PHY_DLSCH_UE_DCI
- add mcs, round, first_rb, nb_rb, TBS to ENB_PHY_ULSCH_UE_DCI

           1-issue#35: miss dci detection
           2-issue#36: ack/nack on pusch are badly encoded
           3-issue#37: ack/nack are sent on pucch instead of pusch

Something went wrong somewhere in the commit history, the function
was not correct.

The most obvious symptom was that way too much SR (scheduling requests)
were given to the UE whenever it had some PUCCH to send.

The case for TDD has not been tested.

           1- timing Advance fix
           2- harq UL fix