The name NR_UE_list_t is misleading: beyond being a simple "list", this
structure carries all/most UE-related MAC information. If at all, it is
a container for multiple lists. The next commit introduces a
NR_UE_list_t structure that organizes UEs in lists such that it is
easier to go through the UEs.

when in phy test, only schedule UE to be in slot 8

nr_configure_pdcch() allocates the CCE, but this is not wanted, e.g., in
multi-user scheduling, since it might not be possible to allocate the
CCEs for these UEs. This commit makes the following changes:

- remove CCE allocation in nr_configure_pdcch()
- remove coreset search in nr_configure_pdcch()
- add functions get_coreset() and get_searchspace() to retrieve coresets
  and search spaces easily
- in nr_fill_nfapi_dl_pdu(), add extra parameters for aggregation level
  and CCE indices and the searchspace and coreset of a UE, which might
  be different for each UE
- allocate CCEs manually in phytest, RA, and DLSCH schedulers

Integration 2020 wk38

See merge request oai/openairinterface5g!899

Merge remote-tracking branch 'origin/fix-0509-crash-RRCConnectionReconfiguration' into integration_2020_wk38

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

    also correction for Circular Dependency Protection on header files
    also correction on the banner check
Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Signed-off-by: Sergey Aranovskiy <aranovskiy@mwnts.ru>

RLC has timers. We need to keep track of time. We chose to not use
realtime but 'processing time'. That is we send a tick to RLC for every
subframe when it is processed by the softmodem. Before this commit we
used to increase time in the function mac_rlc_status_ind which is called
for every subframe in the eNB, but not in the gNB (at least not in the
current gNB). So we need another way to keep track of time.

The function gNB_dlsch_ulsch_scheduler is called for every slot. It seems
to be the perfect candidate to send a tick to RLC for every subframe. We
take care of subcarrier spacing to send every subframe (one subframe is
always 1ms), not every slot (slot duration depends on subcarrier spacing).

It may not be the best solution. To be revised if needed.

Note: the UE has not been fixed. Some modification is needed for the UE
too, most probably.

Create a temporary rrc_eNB_ue_context_t when it can't be obtained from
current RRC state:
- if UE was not attached to current eNB
- when RRCConnectionReestablishmentRequest has a wrong encoding
- in all other cases when ue_context_p can't be obtained.
Signed-off-by: Sergey Aranovskiy <aranovskiy@mwnts.ru>