Integration 2020 wk44

MR923 : Fixes tun  
TUN-interface related changes

MR925 : bugfix: fix frequencies in nr_bandtable    
The array nr_bandtable has then been reviewed fully and all the values that were wrong have been changed.   The check of correctness was done using the website https://www.sqimway.com/nr_band.php  
  
MR931 : Finalize oaicn integration (CI)  
In addition, the "known unstable scenarios" are highlighted in the CI HTML reports.

MR917 : NR CSI reporting
This is a new feature

- it shall be updated at every last PBCH symbol
- this fixes stability issues with the FDD mode

- removed redundant initialisation of variables
- introduced two "RF helpers" function that are replacing shared code in the sync routines
- added a new .c file and updated the cmakelists and .h files

- got rid of global variable fp
- code cleanup, removed redundant and unused code
- removed unused command line options and variables
- grouped command line setting in set_options function

- the band is coming from the SI, therefore a function to get the band is not
  necessary
- this solves also the limitations of the get_band algorithm with the NR bands
  overlapping in the NR operating bands table (e.g. band 78 and band 48)

- this reflects the implementation of IF and IF offset in the gNB RU
- the RF frequencies are set at HW level while the target frequencies are
  stored in fp, therefore the values stored in fp should not be changed
  after sync as only the tx/rx freq is updated
- removed overwritten dl/ul carrier frequencies in fp after sync
- removed redundant set of tx/rx freq in ue_synch (done in init_openair0)
- removed irrelevant set of dl/ul carrier freq in get_options

- tdd_table is filled in only in TDD mode and should not be used in FDD mode

- adapted the get_band function: the algorithm is now taking into account
  also the UL frequency in order to fetch the proper band (this was failing
  before as some NR bands have the same DL band, e.g. band 65 and 66)
- added new bands to the NR table as per TS 38.101 V16.4.0 (2020)
- made the from_nrarfcn function compatible with UL FDD (this function,
  used for both DL and UL  was previously working with TDD only as it
  did not compute properly the frequency for the UL FDD, throwing asserts)
- introduced common functions to get the NR table idx and the duplex mode,
  removing repeated code in the process
- removed the unused function to get the uldl offset
- improved some logging
- other minor fixes to the relevant code

- removed long-time commented out and unused code
- fixed logging

- the RU now supports IF equipment with custom FR1 TX/RX frequencies
- this configuration parameter together with the if_freq parameter allows
  to set a custom IF RX frequency for the gNB
- if the IF offset is not specified, legacy code applies

Merge remote-tracking branch 'origin/oc-docker-october-improvements' into finalize-oaicn-integration

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

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

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

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

Integration 2020 wk42 (2)

MR921 : Hotfix for DL DCI issue in UE  
Fixing a bug from last MR.  
Fix in nr_dlsim that prevents reporting false 'PDSCH ok' message

MR915 : Fix to avoid RRC->X2AP ticking every msec when x2ap task is not enabled  
The aim of itti RRC_SUBFRAME_PROCESS message (MAC->RRC) is to trigger an itti X2AP_SUBFRAME_PROCESS message (RRC->X2AP)  
This change avoids creating RRC_SUBFRAME_PROCESS message if x2ap task is not enabled

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

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

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